Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1655 insertions, 0 deletions

diff --git a/third_party/dav1d/src/obu.c b/third_party/dav1d/src/obu.c
new file mode 100644
index 0000000000..bd117944a8
--- /dev/null
+++ b/third_party/dav1d/src/obu.c
@@ -0,0 +1,1655 @@
+/*
+ * Copyright © 2018-2021, VideoLAN and dav1d authors
+ * Copyright © 2018, Two Orioles, LLC
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+
+#include "dav1d/data.h"
+
+#include "common/frame.h"
+#include "common/intops.h"
+
+#include "src/decode.h"
+#include "src/getbits.h"
+#include "src/levels.h"
+#include "src/log.h"
+#include "src/obu.h"
+#include "src/ref.h"
+#include "src/thread_task.h"
+
+static int parse_seq_hdr(Dav1dContext *const c, GetBits *const gb,
+                         Dav1dSequenceHeader *const hdr)
+{
+#define DEBUG_SEQ_HDR 0
+
+#if DEBUG_SEQ_HDR
+    const unsigned init_bit_pos = dav1d_get_bits_pos(gb);
+#endif
+
+    hdr->profile = dav1d_get_bits(gb, 3);
+    if (hdr->profile > 2) goto error;
+#if DEBUG_SEQ_HDR
+    printf("SEQHDR: post-profile: off=%u\n",
+           dav1d_get_bits_pos(gb) - init_bit_pos);
+#endif
+
+    hdr->still_picture = dav1d_get_bits(gb, 1);
+    hdr->reduced_still_picture_header = dav1d_get_bits(gb, 1);
+    if (hdr->reduced_still_picture_header && !hdr->still_picture) goto error;
+#if DEBUG_SEQ_HDR
+    printf("SEQHDR: post-stillpicture_flags: off=%u\n",
+           dav1d_get_bits_pos(gb) - init_bit_pos);
+#endif
+
+    if (hdr->reduced_still_picture_header) {
+        hdr->timing_info_present = 0;
+        hdr->decoder_model_info_present = 0;
+        hdr->display_model_info_present = 0;
+        hdr->num_operating_points = 1;
+        hdr->operating_points[0].idc = 0;
+        hdr->operating_points[0].major_level = dav1d_get_bits(gb, 3);
+        hdr->operating_points[0].minor_level = dav1d_get_bits(gb, 2);
+        hdr->operating_points[0].tier = 0;
+        hdr->operating_points[0].decoder_model_param_present = 0;
+        hdr->operating_points[0].display_model_param_present = 0;
+    } else {
+        hdr->timing_info_present = dav1d_get_bits(gb, 1);
+        if (hdr->timing_info_present) {
+            hdr->num_units_in_tick = dav1d_get_bits(gb, 32);
+            hdr->time_scale = dav1d_get_bits(gb, 32);
+            hdr->equal_picture_interval = dav1d_get_bits(gb, 1);
+            if (hdr->equal_picture_interval) {
+                const unsigned num_ticks_per_picture = dav1d_get_vlc(gb);
+                if (num_ticks_per_picture == 0xFFFFFFFFU)
+                    goto error;
+                hdr->num_ticks_per_picture = num_ticks_per_picture + 1;
+            }
+
+            hdr->decoder_model_info_present = dav1d_get_bits(gb, 1);
+            if (hdr->decoder_model_info_present) {
+                hdr->encoder_decoder_buffer_delay_length = dav1d_get_bits(gb, 5) + 1;
+                hdr->num_units_in_decoding_tick = dav1d_get_bits(gb, 32);
+                hdr->buffer_removal_delay_length = dav1d_get_bits(gb, 5) + 1;
+                hdr->frame_presentation_delay_length = dav1d_get_bits(gb, 5) + 1;
+            }
+        } else {
+            hdr->decoder_model_info_present = 0;
+        }
+#if DEBUG_SEQ_HDR
+        printf("SEQHDR: post-timinginfo: off=%u\n",
+               dav1d_get_bits_pos(gb) - init_bit_pos);
+#endif
+
+        hdr->display_model_info_present = dav1d_get_bits(gb, 1);
+        hdr->num_operating_points = dav1d_get_bits(gb, 5) + 1;
+        for (int i = 0; i < hdr->num_operating_points; i++) {
+            struct Dav1dSequenceHeaderOperatingPoint *const op =
+                &hdr->operating_points[i];
+            op->idc = dav1d_get_bits(gb, 12);
+            if (op->idc && (!(op->idc & 0xff) || !(op->idc & 0xf00)))
+                goto error;
+            op->major_level = 2 + dav1d_get_bits(gb, 3);
+            op->minor_level = dav1d_get_bits(gb, 2);
+            op->tier = op->major_level > 3 ? dav1d_get_bits(gb, 1) : 0;
+            op->decoder_model_param_present =
+                hdr->decoder_model_info_present && dav1d_get_bits(gb, 1);
+            if (op->decoder_model_param_present) {
+                struct Dav1dSequenceHeaderOperatingParameterInfo *const opi =
+                    &hdr->operating_parameter_info[i];
+                opi->decoder_buffer_delay =
+                    dav1d_get_bits(gb, hdr->encoder_decoder_buffer_delay_length);
+                opi->encoder_buffer_delay =
+                    dav1d_get_bits(gb, hdr->encoder_decoder_buffer_delay_length);
+                opi->low_delay_mode = dav1d_get_bits(gb, 1);
+            }
+            op->display_model_param_present =
+                hdr->display_model_info_present && dav1d_get_bits(gb, 1);
+            if (op->display_model_param_present) {
+                op->initial_display_delay = dav1d_get_bits(gb, 4) + 1;
+            }
+        }
+#if DEBUG_SEQ_HDR
+        printf("SEQHDR: post-operating-points: off=%u\n",
+               dav1d_get_bits_pos(gb) - init_bit_pos);
+#endif
+    }
+
+    const int op_idx =
+        c->operating_point < hdr->num_operating_points ? c->operating_point : 0;
+    c->operating_point_idc = hdr->operating_points[op_idx].idc;
+    const unsigned spatial_mask = c->operating_point_idc >> 8;
+    c->max_spatial_id = spatial_mask ? ulog2(spatial_mask) : 0;
+
+    hdr->width_n_bits = dav1d_get_bits(gb, 4) + 1;
+    hdr->height_n_bits = dav1d_get_bits(gb, 4) + 1;
+    hdr->max_width = dav1d_get_bits(gb, hdr->width_n_bits) + 1;
+    hdr->max_height = dav1d_get_bits(gb, hdr->height_n_bits) + 1;
+#if DEBUG_SEQ_HDR
+    printf("SEQHDR: post-size: off=%u\n",
+           dav1d_get_bits_pos(gb) - init_bit_pos);
+#endif
+    hdr->frame_id_numbers_present =
+        hdr->reduced_still_picture_header ? 0 : dav1d_get_bits(gb, 1);
+    if (hdr->frame_id_numbers_present) {
+        hdr->delta_frame_id_n_bits = dav1d_get_bits(gb, 4) + 2;
+        hdr->frame_id_n_bits = dav1d_get_bits(gb, 3) + hdr->delta_frame_id_n_bits + 1;
+    }
+#if DEBUG_SEQ_HDR
+    printf("SEQHDR: post-frame-id-numbers-present: off=%u\n",
+           dav1d_get_bits_pos(gb) - init_bit_pos);
+#endif
+
+    hdr->sb128 = dav1d_get_bits(gb, 1);
+    hdr->filter_intra = dav1d_get_bits(gb, 1);
+    hdr->intra_edge_filter = dav1d_get_bits(gb, 1);
+    if (hdr->reduced_still_picture_header) {
+        hdr->inter_intra = 0;
+        hdr->masked_compound = 0;
+        hdr->warped_motion = 0;
+        hdr->dual_filter = 0;
+        hdr->order_hint = 0;
+        hdr->jnt_comp = 0;
+        hdr->ref_frame_mvs = 0;
+        hdr->order_hint_n_bits = 0;
+        hdr->screen_content_tools = DAV1D_ADAPTIVE;
+        hdr->force_integer_mv = DAV1D_ADAPTIVE;
+    } else {
+        hdr->inter_intra = dav1d_get_bits(gb, 1);
+        hdr->masked_compound = dav1d_get_bits(gb, 1);
+        hdr->warped_motion = dav1d_get_bits(gb, 1);
+        hdr->dual_filter = dav1d_get_bits(gb, 1);
+        hdr->order_hint = dav1d_get_bits(gb, 1);
+        if (hdr->order_hint) {
+            hdr->jnt_comp = dav1d_get_bits(gb, 1);
+            hdr->ref_frame_mvs = dav1d_get_bits(gb, 1);
+        } else {
+            hdr->jnt_comp = 0;
+            hdr->ref_frame_mvs = 0;
+            hdr->order_hint_n_bits = 0;
+        }
+        hdr->screen_content_tools = dav1d_get_bits(gb, 1) ? DAV1D_ADAPTIVE : dav1d_get_bits(gb, 1);
+    #if DEBUG_SEQ_HDR
+        printf("SEQHDR: post-screentools: off=%u\n",
+               dav1d_get_bits_pos(gb) - init_bit_pos);
+    #endif
+        hdr->force_integer_mv = hdr->screen_content_tools ?
+                                dav1d_get_bits(gb, 1) ? DAV1D_ADAPTIVE : dav1d_get_bits(gb, 1) : 2;
+        if (hdr->order_hint)
+            hdr->order_hint_n_bits = dav1d_get_bits(gb, 3) + 1;
+    }
+    hdr->super_res = dav1d_get_bits(gb, 1);
+    hdr->cdef = dav1d_get_bits(gb, 1);
+    hdr->restoration = dav1d_get_bits(gb, 1);
+#if DEBUG_SEQ_HDR
+    printf("SEQHDR: post-featurebits: off=%u\n",
+           dav1d_get_bits_pos(gb) - init_bit_pos);
+#endif
+
+    hdr->hbd = dav1d_get_bits(gb, 1);
+    if (hdr->profile == 2 && hdr->hbd) hdr->hbd += dav1d_get_bits(gb, 1);
+    hdr->monochrome = hdr->profile != 1 ? dav1d_get_bits(gb, 1) : 0;
+    hdr->color_description_present = dav1d_get_bits(gb, 1);
+    if (hdr->color_description_present) {
+        hdr->pri = dav1d_get_bits(gb, 8);
+        hdr->trc = dav1d_get_bits(gb, 8);
+        hdr->mtrx = dav1d_get_bits(gb, 8);
+    } else {
+        hdr->pri = DAV1D_COLOR_PRI_UNKNOWN;
+        hdr->trc = DAV1D_TRC_UNKNOWN;
+        hdr->mtrx = DAV1D_MC_UNKNOWN;
+    }
+    if (hdr->monochrome) {
+        hdr->color_range = dav1d_get_bits(gb, 1);
+        hdr->layout = DAV1D_PIXEL_LAYOUT_I400;
+        hdr->ss_hor = hdr->ss_ver = 1;
+        hdr->chr = DAV1D_CHR_UNKNOWN;
+        hdr->separate_uv_delta_q = 0;
+    } else if (hdr->pri == DAV1D_COLOR_PRI_BT709 &&
+               hdr->trc == DAV1D_TRC_SRGB &&
+               hdr->mtrx == DAV1D_MC_IDENTITY)
+    {
+        hdr->layout = DAV1D_PIXEL_LAYOUT_I444;
+        hdr->ss_hor = hdr->ss_ver = 0;
+        hdr->color_range = 1;
+        if (hdr->profile != 1 && !(hdr->profile == 2 && hdr->hbd == 2))
+            goto error;
+    } else {
+        hdr->color_range = dav1d_get_bits(gb, 1);
+        switch (hdr->profile) {
+        case 0: hdr->layout = DAV1D_PIXEL_LAYOUT_I420;
+                hdr->ss_hor = hdr->ss_ver = 1;
+                break;
+        case 1: hdr->layout = DAV1D_PIXEL_LAYOUT_I444;
+                hdr->ss_hor = hdr->ss_ver = 0;
+                break;
+        case 2:
+            if (hdr->hbd == 2) {
+                hdr->ss_hor = dav1d_get_bits(gb, 1);
+                hdr->ss_ver = hdr->ss_hor && dav1d_get_bits(gb, 1);
+            } else {
+                hdr->ss_hor = 1;
+                hdr->ss_ver = 0;
+            }
+            hdr->layout = hdr->ss_hor ?
+                          hdr->ss_ver ? DAV1D_PIXEL_LAYOUT_I420 :
+                                        DAV1D_PIXEL_LAYOUT_I422 :
+                                        DAV1D_PIXEL_LAYOUT_I444;
+            break;
+        }
+        hdr->chr = hdr->ss_hor == 1 && hdr->ss_ver == 1 ?
+                   dav1d_get_bits(gb, 2) : DAV1D_CHR_UNKNOWN;
+    }
+    if (c->strict_std_compliance &&
+        hdr->mtrx == DAV1D_MC_IDENTITY && hdr->layout != DAV1D_PIXEL_LAYOUT_I444)
+    {
+        goto error;
+    }
+    hdr->separate_uv_delta_q = !hdr->monochrome && dav1d_get_bits(gb, 1);
+#if DEBUG_SEQ_HDR
+    printf("SEQHDR: post-colorinfo: off=%u\n",
+           dav1d_get_bits_pos(gb) - init_bit_pos);
+#endif
+
+    hdr->film_grain_present = dav1d_get_bits(gb, 1);
+#if DEBUG_SEQ_HDR
+    printf("SEQHDR: post-filmgrain: off=%u\n",
+           dav1d_get_bits_pos(gb) - init_bit_pos);
+#endif
+
+    dav1d_get_bits(gb, 1); // dummy bit
+
+    // We needn't bother flushing the OBU here: we'll check we didn't
+    // overrun in the caller and will then discard gb, so there's no
+    // point in setting its position properly.
+
+    return 0;
+
+error:
+    dav1d_log(c, "Error parsing sequence header\n");
+    return DAV1D_ERR(EINVAL);
+}
+
+static int read_frame_size(Dav1dContext *const c, GetBits *const gb,
+                           const int use_ref)
+{
+    const Dav1dSequenceHeader *const seqhdr = c->seq_hdr;
+    Dav1dFrameHeader *const hdr = c->frame_hdr;
+
+    if (use_ref) {
+        for (int i = 0; i < 7; i++) {
+            if (dav1d_get_bits(gb, 1)) {
+                const Dav1dThreadPicture *const ref =
+                    &c->refs[c->frame_hdr->refidx[i]].p;
+                if (!ref->p.data[0]) return -1;
+                hdr->width[1] = ref->p.p.w;
+                hdr->height = ref->p.p.h;
+                hdr->render_width = ref->p.frame_hdr->render_width;
+                hdr->render_height = ref->p.frame_hdr->render_height;
+                hdr->super_res.enabled = seqhdr->super_res && dav1d_get_bits(gb, 1);
+                if (hdr->super_res.enabled) {
+                    const int d = hdr->super_res.width_scale_denominator =
+                        9 + dav1d_get_bits(gb, 3);
+                    hdr->width[0] = imax((hdr->width[1] * 8 + (d >> 1)) / d,
+                                         imin(16, hdr->width[1]));
+                } else {
+                    hdr->super_res.width_scale_denominator = 8;
+                    hdr->width[0] = hdr->width[1];
+                }
+                return 0;
+            }
+        }
+    }
+
+    if (hdr->frame_size_override) {
+        hdr->width[1] = dav1d_get_bits(gb, seqhdr->width_n_bits) + 1;
+        hdr->height = dav1d_get_bits(gb, seqhdr->height_n_bits) + 1;
+    } else {
+        hdr->width[1] = seqhdr->max_width;
+        hdr->height = seqhdr->max_height;
+    }
+    hdr->super_res.enabled = seqhdr->super_res && dav1d_get_bits(gb, 1);
+    if (hdr->super_res.enabled) {
+        const int d = hdr->super_res.width_scale_denominator = 9 + dav1d_get_bits(gb, 3);
+        hdr->width[0] = imax((hdr->width[1] * 8 + (d >> 1)) / d, imin(16, hdr->width[1]));
+    } else {
+        hdr->super_res.width_scale_denominator = 8;
+        hdr->width[0] = hdr->width[1];
+    }
+    hdr->have_render_size = dav1d_get_bits(gb, 1);
+    if (hdr->have_render_size) {
+        hdr->render_width = dav1d_get_bits(gb, 16) + 1;
+        hdr->render_height = dav1d_get_bits(gb, 16) + 1;
+    } else {
+        hdr->render_width = hdr->width[1];
+        hdr->render_height = hdr->height;
+    }
+    return 0;
+}
+
+static inline int tile_log2(const int sz, const int tgt) {
+    int k;
+    for (k = 0; (sz << k) < tgt; k++) ;
+    return k;
+}
+
+static const Dav1dLoopfilterModeRefDeltas default_mode_ref_deltas = {
+    .mode_delta = { 0, 0 },
+    .ref_delta = { 1, 0, 0, 0, -1, 0, -1, -1 },
+};
+
+static int parse_frame_hdr(Dav1dContext *const c, GetBits *const gb) {
+#define DEBUG_FRAME_HDR 0
+
+#if DEBUG_FRAME_HDR
+    const uint8_t *const init_ptr = gb->ptr;
+#endif
+    const Dav1dSequenceHeader *const seqhdr = c->seq_hdr;
+    Dav1dFrameHeader *const hdr = c->frame_hdr;
+
+    hdr->show_existing_frame =
+        !seqhdr->reduced_still_picture_header && dav1d_get_bits(gb, 1);
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-show_existing_frame: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+    if (hdr->show_existing_frame) {
+        hdr->existing_frame_idx = dav1d_get_bits(gb, 3);
+        if (seqhdr->decoder_model_info_present && !seqhdr->equal_picture_interval)
+            hdr->frame_presentation_delay = dav1d_get_bits(gb, seqhdr->frame_presentation_delay_length);
+        if (seqhdr->frame_id_numbers_present) {
+            hdr->frame_id = dav1d_get_bits(gb, seqhdr->frame_id_n_bits);
+            Dav1dFrameHeader *const ref_frame_hdr = c->refs[hdr->existing_frame_idx].p.p.frame_hdr;
+            if (!ref_frame_hdr || ref_frame_hdr->frame_id != hdr->frame_id) goto error;
+        }
+        return 0;
+    }
+
+    hdr->frame_type = seqhdr->reduced_still_picture_header ? DAV1D_FRAME_TYPE_KEY : dav1d_get_bits(gb, 2);
+    hdr->show_frame = seqhdr->reduced_still_picture_header || dav1d_get_bits(gb, 1);
+    if (hdr->show_frame) {
+        if (seqhdr->decoder_model_info_present && !seqhdr->equal_picture_interval)
+            hdr->frame_presentation_delay = dav1d_get_bits(gb, seqhdr->frame_presentation_delay_length);
+        hdr->showable_frame = hdr->frame_type != DAV1D_FRAME_TYPE_KEY;
+    } else
+        hdr->showable_frame = dav1d_get_bits(gb, 1);
+    hdr->error_resilient_mode =
+        (hdr->frame_type == DAV1D_FRAME_TYPE_KEY && hdr->show_frame) ||
+        hdr->frame_type == DAV1D_FRAME_TYPE_SWITCH ||
+        seqhdr->reduced_still_picture_header || dav1d_get_bits(gb, 1);
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-frametype_bits: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+    hdr->disable_cdf_update = dav1d_get_bits(gb, 1);
+    hdr->allow_screen_content_tools = seqhdr->screen_content_tools == DAV1D_ADAPTIVE ?
+                                 dav1d_get_bits(gb, 1) : seqhdr->screen_content_tools;
+    if (hdr->allow_screen_content_tools)
+        hdr->force_integer_mv = seqhdr->force_integer_mv == DAV1D_ADAPTIVE ?
+                                dav1d_get_bits(gb, 1) : seqhdr->force_integer_mv;
+    else
+        hdr->force_integer_mv = 0;
+
+    if (IS_KEY_OR_INTRA(hdr))
+        hdr->force_integer_mv = 1;
+
+    if (seqhdr->frame_id_numbers_present)
+        hdr->frame_id = dav1d_get_bits(gb, seqhdr->frame_id_n_bits);
+
+    hdr->frame_size_override = seqhdr->reduced_still_picture_header ? 0 :
+                               hdr->frame_type == DAV1D_FRAME_TYPE_SWITCH ? 1 : dav1d_get_bits(gb, 1);
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-frame_size_override_flag: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+    hdr->frame_offset = seqhdr->order_hint ?
+                        dav1d_get_bits(gb, seqhdr->order_hint_n_bits) : 0;
+    hdr->primary_ref_frame = !hdr->error_resilient_mode && IS_INTER_OR_SWITCH(hdr) ?
+                             dav1d_get_bits(gb, 3) : DAV1D_PRIMARY_REF_NONE;
+
+    if (seqhdr->decoder_model_info_present) {
+        hdr->buffer_removal_time_present = dav1d_get_bits(gb, 1);
+        if (hdr->buffer_removal_time_present) {
+            for (int i = 0; i < c->seq_hdr->num_operating_points; i++) {
+                const struct Dav1dSequenceHeaderOperatingPoint *const seqop = &seqhdr->operating_points[i];
+                struct Dav1dFrameHeaderOperatingPoint *const op = &hdr->operating_points[i];
+                if (seqop->decoder_model_param_present) {
+                    int in_temporal_layer = (seqop->idc >> hdr->temporal_id) & 1;
+                    int in_spatial_layer  = (seqop->idc >> (hdr->spatial_id + 8)) & 1;
+                    if (!seqop->idc || (in_temporal_layer && in_spatial_layer))
+                        op->buffer_removal_time = dav1d_get_bits(gb, seqhdr->buffer_removal_delay_length);
+                }
+            }
+        }
+    }
+
+    if (IS_KEY_OR_INTRA(hdr)) {
+        hdr->refresh_frame_flags = (hdr->frame_type == DAV1D_FRAME_TYPE_KEY &&
+                                    hdr->show_frame) ? 0xff : dav1d_get_bits(gb, 8);
+        if (hdr->refresh_frame_flags != 0xff && hdr->error_resilient_mode && seqhdr->order_hint)
+            for (int i = 0; i < 8; i++)
+                dav1d_get_bits(gb, seqhdr->order_hint_n_bits);
+        if (c->strict_std_compliance &&
+            hdr->frame_type == DAV1D_FRAME_TYPE_INTRA && hdr->refresh_frame_flags == 0xff)
+        {
+            goto error;
+        }
+        if (read_frame_size(c, gb, 0) < 0) goto error;
+        hdr->allow_intrabc = hdr->allow_screen_content_tools &&
+                             !hdr->super_res.enabled && dav1d_get_bits(gb, 1);
+        hdr->use_ref_frame_mvs = 0;
+    } else {
+        hdr->allow_intrabc = 0;
+        hdr->refresh_frame_flags = hdr->frame_type == DAV1D_FRAME_TYPE_SWITCH ? 0xff :
+                                   dav1d_get_bits(gb, 8);
+        if (hdr->error_resilient_mode && seqhdr->order_hint)
+            for (int i = 0; i < 8; i++)
+                dav1d_get_bits(gb, seqhdr->order_hint_n_bits);
+        hdr->frame_ref_short_signaling =
+            seqhdr->order_hint && dav1d_get_bits(gb, 1);
+        if (hdr->frame_ref_short_signaling) { // FIXME: Nearly verbatim copy from section 7.8
+            hdr->refidx[0] = dav1d_get_bits(gb, 3);
+            hdr->refidx[1] = hdr->refidx[2] = -1;
+            hdr->refidx[3] = dav1d_get_bits(gb, 3);
+            hdr->refidx[4] = hdr->refidx[5] = hdr->refidx[6] = -1;
+
+            int shifted_frame_offset[8];
+            const int current_frame_offset = 1 << (seqhdr->order_hint_n_bits - 1);
+            for (int i = 0; i < 8; i++) {
+                if (!c->refs[i].p.p.frame_hdr) goto error;
+                shifted_frame_offset[i] = current_frame_offset +
+                    get_poc_diff(seqhdr->order_hint_n_bits,
+                                 c->refs[i].p.p.frame_hdr->frame_offset,
+                                 hdr->frame_offset);
+            }
+
+            int used_frame[8] = { 0 };
+            used_frame[hdr->refidx[0]] = 1;
+            used_frame[hdr->refidx[3]] = 1;
+
+            int latest_frame_offset = -1;
+            for (int i = 0; i < 8; i++) {
+                const int hint = shifted_frame_offset[i];
+                if (!used_frame[i] && hint >= current_frame_offset &&
+                    hint >= latest_frame_offset)
+                {
+                    hdr->refidx[6] = i;
+                    latest_frame_offset = hint;
+                }
+            }
+            if (latest_frame_offset != -1)
+                used_frame[hdr->refidx[6]] = 1;
+
+            int earliest_frame_offset = INT_MAX;
+            for (int i = 0; i < 8; i++) {
+                const int hint = shifted_frame_offset[i];
+                if (!used_frame[i] && hint >= current_frame_offset &&
+                    hint < earliest_frame_offset)
+                {
+                    hdr->refidx[4] = i;
+                    earliest_frame_offset = hint;
+                }
+            }
+            if (earliest_frame_offset != INT_MAX)
+                used_frame[hdr->refidx[4]] = 1;
+
+            earliest_frame_offset = INT_MAX;
+            for (int i = 0; i < 8; i++) {
+                const int hint = shifted_frame_offset[i];
+                if (!used_frame[i] && hint >= current_frame_offset &&
+                    (hint < earliest_frame_offset))
+                {
+                    hdr->refidx[5] = i;
+                    earliest_frame_offset = hint;
+                }
+            }
+            if (earliest_frame_offset != INT_MAX)
+                used_frame[hdr->refidx[5]] = 1;
+
+            for (int i = 1; i < 7; i++) {
+                if (hdr->refidx[i] < 0) {
+                    latest_frame_offset = -1;
+                    for (int j = 0; j < 8; j++) {
+                        const int hint = shifted_frame_offset[j];
+                        if (!used_frame[j] && hint < current_frame_offset &&
+                            hint >= latest_frame_offset)
+                        {
+                            hdr->refidx[i] = j;
+                            latest_frame_offset = hint;
+                        }
+                    }
+                    if (latest_frame_offset != -1)
+                        used_frame[hdr->refidx[i]] = 1;
+                }
+            }
+
+            earliest_frame_offset = INT_MAX;
+            int ref = -1;
+            for (int i = 0; i < 8; i++) {
+                const int hint = shifted_frame_offset[i];
+                if (hint < earliest_frame_offset) {
+                    ref = i;
+                    earliest_frame_offset = hint;
+                }
+            }
+            for (int i = 0; i < 7; i++) {
+                if (hdr->refidx[i] < 0)
+                    hdr->refidx[i] = ref;
+            }
+        }
+        for (int i = 0; i < 7; i++) {
+            if (!hdr->frame_ref_short_signaling)
+                hdr->refidx[i] = dav1d_get_bits(gb, 3);
+            if (seqhdr->frame_id_numbers_present) {
+                const int delta_ref_frame_id_minus_1 = dav1d_get_bits(gb, seqhdr->delta_frame_id_n_bits);
+                const int ref_frame_id = (hdr->frame_id + (1 << seqhdr->frame_id_n_bits) - delta_ref_frame_id_minus_1 - 1) & ((1 << seqhdr->frame_id_n_bits) - 1);
+                Dav1dFrameHeader *const ref_frame_hdr = c->refs[hdr->refidx[i]].p.p.frame_hdr;
+                if (!ref_frame_hdr || ref_frame_hdr->frame_id != ref_frame_id) goto error;
+            }
+        }
+        const int use_ref = !hdr->error_resilient_mode &&
+                            hdr->frame_size_override;
+        if (read_frame_size(c, gb, use_ref) < 0) goto error;
+        hdr->hp = !hdr->force_integer_mv && dav1d_get_bits(gb, 1);
+        hdr->subpel_filter_mode = dav1d_get_bits(gb, 1) ? DAV1D_FILTER_SWITCHABLE :
+                                                          dav1d_get_bits(gb, 2);
+        hdr->switchable_motion_mode = dav1d_get_bits(gb, 1);
+        hdr->use_ref_frame_mvs = !hdr->error_resilient_mode &&
+            seqhdr->ref_frame_mvs && seqhdr->order_hint &&
+            IS_INTER_OR_SWITCH(hdr) && dav1d_get_bits(gb, 1);
+    }
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-frametype-specific-bits: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+
+    hdr->refresh_context = !seqhdr->reduced_still_picture_header &&
+                           !hdr->disable_cdf_update && !dav1d_get_bits(gb, 1);
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-refresh_context: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+
+    // tile data
+    hdr->tiling.uniform = dav1d_get_bits(gb, 1);
+    const int sbsz_min1 = (64 << seqhdr->sb128) - 1;
+    const int sbsz_log2 = 6 + seqhdr->sb128;
+    const int sbw = (hdr->width[0] + sbsz_min1) >> sbsz_log2;
+    const int sbh = (hdr->height + sbsz_min1) >> sbsz_log2;
+    const int max_tile_width_sb = 4096 >> sbsz_log2;
+    const int max_tile_area_sb = 4096 * 2304 >> (2 * sbsz_log2);
+    hdr->tiling.min_log2_cols = tile_log2(max_tile_width_sb, sbw);
+    hdr->tiling.max_log2_cols = tile_log2(1, imin(sbw, DAV1D_MAX_TILE_COLS));
+    hdr->tiling.max_log2_rows = tile_log2(1, imin(sbh, DAV1D_MAX_TILE_ROWS));
+    const int min_log2_tiles = imax(tile_log2(max_tile_area_sb, sbw * sbh),
+                              hdr->tiling.min_log2_cols);
+    if (hdr->tiling.uniform) {
+        for (hdr->tiling.log2_cols = hdr->tiling.min_log2_cols;
+             hdr->tiling.log2_cols < hdr->tiling.max_log2_cols && dav1d_get_bits(gb, 1);
+             hdr->tiling.log2_cols++) ;
+        const int tile_w = 1 + ((sbw - 1) >> hdr->tiling.log2_cols);
+        hdr->tiling.cols = 0;
+        for (int sbx = 0; sbx < sbw; sbx += tile_w, hdr->tiling.cols++)
+            hdr->tiling.col_start_sb[hdr->tiling.cols] = sbx;
+        hdr->tiling.min_log2_rows =
+            imax(min_log2_tiles - hdr->tiling.log2_cols, 0);
+
+        for (hdr->tiling.log2_rows = hdr->tiling.min_log2_rows;
+             hdr->tiling.log2_rows < hdr->tiling.max_log2_rows && dav1d_get_bits(gb, 1);
+             hdr->tiling.log2_rows++) ;
+        const int tile_h = 1 + ((sbh - 1) >> hdr->tiling.log2_rows);
+        hdr->tiling.rows = 0;
+        for (int sby = 0; sby < sbh; sby += tile_h, hdr->tiling.rows++)
+            hdr->tiling.row_start_sb[hdr->tiling.rows] = sby;
+    } else {
+        hdr->tiling.cols = 0;
+        int widest_tile = 0, max_tile_area_sb = sbw * sbh;
+        for (int sbx = 0; sbx < sbw && hdr->tiling.cols < DAV1D_MAX_TILE_COLS; hdr->tiling.cols++) {
+            const int tile_width_sb = imin(sbw - sbx, max_tile_width_sb);
+            const int tile_w = (tile_width_sb > 1) ?
+                                   1 + dav1d_get_uniform(gb, tile_width_sb) :
+                                   1;
+            hdr->tiling.col_start_sb[hdr->tiling.cols] = sbx;
+            sbx += tile_w;
+            widest_tile = imax(widest_tile, tile_w);
+        }
+        hdr->tiling.log2_cols = tile_log2(1, hdr->tiling.cols);
+        if (min_log2_tiles) max_tile_area_sb >>= min_log2_tiles + 1;
+        const int max_tile_height_sb = imax(max_tile_area_sb / widest_tile, 1);
+
+        hdr->tiling.rows = 0;
+        for (int sby = 0; sby < sbh && hdr->tiling.rows < DAV1D_MAX_TILE_ROWS; hdr->tiling.rows++) {
+            const int tile_height_sb = imin(sbh - sby, max_tile_height_sb);
+            const int tile_h = (tile_height_sb > 1) ?
+                                   1 + dav1d_get_uniform(gb, tile_height_sb) :
+                                   1;
+            hdr->tiling.row_start_sb[hdr->tiling.rows] = sby;
+            sby += tile_h;
+        }
+        hdr->tiling.log2_rows = tile_log2(1, hdr->tiling.rows);
+    }
+    hdr->tiling.col_start_sb[hdr->tiling.cols] = sbw;
+    hdr->tiling.row_start_sb[hdr->tiling.rows] = sbh;
+    if (hdr->tiling.log2_cols || hdr->tiling.log2_rows) {
+        hdr->tiling.update = dav1d_get_bits(gb, hdr->tiling.log2_cols +
+                                                hdr->tiling.log2_rows);
+        if (hdr->tiling.update >= hdr->tiling.cols * hdr->tiling.rows)
+            goto error;
+        hdr->tiling.n_bytes = dav1d_get_bits(gb, 2) + 1;
+    } else {
+        hdr->tiling.n_bytes = hdr->tiling.update = 0;
+    }
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-tiling: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+
+    // quant data
+    hdr->quant.yac = dav1d_get_bits(gb, 8);
+    hdr->quant.ydc_delta = dav1d_get_bits(gb, 1) ? dav1d_get_sbits(gb, 6) : 0;
+    if (!seqhdr->monochrome) {
+        // If the sequence header says that delta_q might be different
+        // for U, V, we must check whether it actually is for this
+        // frame.
+        const int diff_uv_delta = seqhdr->separate_uv_delta_q ? dav1d_get_bits(gb, 1) : 0;
+        hdr->quant.udc_delta = dav1d_get_bits(gb, 1) ? dav1d_get_sbits(gb, 6) : 0;
+        hdr->quant.uac_delta = dav1d_get_bits(gb, 1) ? dav1d_get_sbits(gb, 6) : 0;
+        if (diff_uv_delta) {
+            hdr->quant.vdc_delta = dav1d_get_bits(gb, 1) ? dav1d_get_sbits(gb, 6) : 0;
+            hdr->quant.vac_delta = dav1d_get_bits(gb, 1) ? dav1d_get_sbits(gb, 6) : 0;
+        } else {
+            hdr->quant.vdc_delta = hdr->quant.udc_delta;
+            hdr->quant.vac_delta = hdr->quant.uac_delta;
+        }
+    }
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-quant: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+    hdr->quant.qm = dav1d_get_bits(gb, 1);
+    if (hdr->quant.qm) {
+        hdr->quant.qm_y = dav1d_get_bits(gb, 4);
+        hdr->quant.qm_u = dav1d_get_bits(gb, 4);
+        hdr->quant.qm_v =
+            seqhdr->separate_uv_delta_q ? (int)dav1d_get_bits(gb, 4) :
+                                          hdr->quant.qm_u;
+    }
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-qm: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+
+    // segmentation data
+    hdr->segmentation.enabled = dav1d_get_bits(gb, 1);
+    if (hdr->segmentation.enabled) {
+        if (hdr->primary_ref_frame == DAV1D_PRIMARY_REF_NONE) {
+            hdr->segmentation.update_map = 1;
+            hdr->segmentation.temporal = 0;
+            hdr->segmentation.update_data = 1;
+        } else {
+            hdr->segmentation.update_map = dav1d_get_bits(gb, 1);
+            hdr->segmentation.temporal =
+                hdr->segmentation.update_map ? dav1d_get_bits(gb, 1) : 0;
+            hdr->segmentation.update_data = dav1d_get_bits(gb, 1);
+        }
+
+        if (hdr->segmentation.update_data) {
+            hdr->segmentation.seg_data.preskip = 0;
+            hdr->segmentation.seg_data.last_active_segid = -1;
+            for (int i = 0; i < DAV1D_MAX_SEGMENTS; i++) {
+                Dav1dSegmentationData *const seg =
+                    &hdr->segmentation.seg_data.d[i];
+                if (dav1d_get_bits(gb, 1)) {
+                    seg->delta_q = dav1d_get_sbits(gb, 8);
+                    hdr->segmentation.seg_data.last_active_segid = i;
+                } else {
+                    seg->delta_q = 0;
+                }
+                if (dav1d_get_bits(gb, 1)) {
+                    seg->delta_lf_y_v = dav1d_get_sbits(gb, 6);
+                    hdr->segmentation.seg_data.last_active_segid = i;
+                } else {
+                    seg->delta_lf_y_v = 0;
+                }
+                if (dav1d_get_bits(gb, 1)) {
+                    seg->delta_lf_y_h = dav1d_get_sbits(gb, 6);
+                    hdr->segmentation.seg_data.last_active_segid = i;
+                } else {
+                    seg->delta_lf_y_h = 0;
+                }
+                if (dav1d_get_bits(gb, 1)) {
+                    seg->delta_lf_u = dav1d_get_sbits(gb, 6);
+                    hdr->segmentation.seg_data.last_active_segid = i;
+                } else {
+                    seg->delta_lf_u = 0;
+                }
+                if (dav1d_get_bits(gb, 1)) {
+                    seg->delta_lf_v = dav1d_get_sbits(gb, 6);
+                    hdr->segmentation.seg_data.last_active_segid = i;
+                } else {
+                    seg->delta_lf_v = 0;
+                }
+                if (dav1d_get_bits(gb, 1)) {
+                    seg->ref = dav1d_get_bits(gb, 3);
+                    hdr->segmentation.seg_data.last_active_segid = i;
+                    hdr->segmentation.seg_data.preskip = 1;
+                } else {
+                    seg->ref = -1;
+                }
+                if ((seg->skip = dav1d_get_bits(gb, 1))) {
+                    hdr->segmentation.seg_data.last_active_segid = i;
+                    hdr->segmentation.seg_data.preskip = 1;
+                }
+                if ((seg->globalmv = dav1d_get_bits(gb, 1))) {
+                    hdr->segmentation.seg_data.last_active_segid = i;
+                    hdr->segmentation.seg_data.preskip = 1;
+                }
+            }
+        } else {
+            // segmentation.update_data was false so we should copy
+            // segmentation data from the reference frame.
+            assert(hdr->primary_ref_frame != DAV1D_PRIMARY_REF_NONE);
+            const int pri_ref = hdr->refidx[hdr->primary_ref_frame];
+            if (!c->refs[pri_ref].p.p.frame_hdr) goto error;
+            hdr->segmentation.seg_data =
+                c->refs[pri_ref].p.p.frame_hdr->segmentation.seg_data;
+        }
+    } else {
+        memset(&hdr->segmentation.seg_data, 0, sizeof(Dav1dSegmentationDataSet));
+        for (int i = 0; i < DAV1D_MAX_SEGMENTS; i++)
+            hdr->segmentation.seg_data.d[i].ref = -1;
+    }
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-segmentation: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+
+    // delta q
+    hdr->delta.q.present = hdr->quant.yac ? dav1d_get_bits(gb, 1) : 0;
+    hdr->delta.q.res_log2 = hdr->delta.q.present ? dav1d_get_bits(gb, 2) : 0;
+    hdr->delta.lf.present = hdr->delta.q.present && !hdr->allow_intrabc &&
+                            dav1d_get_bits(gb, 1);
+    hdr->delta.lf.res_log2 = hdr->delta.lf.present ? dav1d_get_bits(gb, 2) : 0;
+    hdr->delta.lf.multi = hdr->delta.lf.present ? dav1d_get_bits(gb, 1) : 0;
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-delta_q_lf_flags: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+
+    // derive lossless flags
+    const int delta_lossless = !hdr->quant.ydc_delta && !hdr->quant.udc_delta &&
+        !hdr->quant.uac_delta && !hdr->quant.vdc_delta && !hdr->quant.vac_delta;
+    hdr->all_lossless = 1;
+    for (int i = 0; i < DAV1D_MAX_SEGMENTS; i++) {
+        hdr->segmentation.qidx[i] = hdr->segmentation.enabled ?
+            iclip_u8(hdr->quant.yac + hdr->segmentation.seg_data.d[i].delta_q) :
+            hdr->quant.yac;
+        hdr->segmentation.lossless[i] =
+            !hdr->segmentation.qidx[i] && delta_lossless;
+        hdr->all_lossless &= hdr->segmentation.lossless[i];
+    }
+
+    // loopfilter
+    if (hdr->all_lossless || hdr->allow_intrabc) {
+        hdr->loopfilter.level_y[0] = hdr->loopfilter.level_y[1] = 0;
+        hdr->loopfilter.level_u = hdr->loopfilter.level_v = 0;
+        hdr->loopfilter.sharpness = 0;
+        hdr->loopfilter.mode_ref_delta_enabled = 1;
+        hdr->loopfilter.mode_ref_delta_update = 1;
+        hdr->loopfilter.mode_ref_deltas = default_mode_ref_deltas;
+    } else {
+        hdr->loopfilter.level_y[0] = dav1d_get_bits(gb, 6);
+        hdr->loopfilter.level_y[1] = dav1d_get_bits(gb, 6);
+        if (!seqhdr->monochrome &&
+            (hdr->loopfilter.level_y[0] || hdr->loopfilter.level_y[1]))
+        {
+            hdr->loopfilter.level_u = dav1d_get_bits(gb, 6);
+            hdr->loopfilter.level_v = dav1d_get_bits(gb, 6);
+        }
+        hdr->loopfilter.sharpness = dav1d_get_bits(gb, 3);
+
+        if (hdr->primary_ref_frame == DAV1D_PRIMARY_REF_NONE) {
+            hdr->loopfilter.mode_ref_deltas = default_mode_ref_deltas;
+        } else {
+            const int ref = hdr->refidx[hdr->primary_ref_frame];
+            if (!c->refs[ref].p.p.frame_hdr) goto error;
+            hdr->loopfilter.mode_ref_deltas =
+                c->refs[ref].p.p.frame_hdr->loopfilter.mode_ref_deltas;
+        }
+        hdr->loopfilter.mode_ref_delta_enabled = dav1d_get_bits(gb, 1);
+        if (hdr->loopfilter.mode_ref_delta_enabled) {
+            hdr->loopfilter.mode_ref_delta_update = dav1d_get_bits(gb, 1);
+            if (hdr->loopfilter.mode_ref_delta_update) {
+                for (int i = 0; i < 8; i++)
+                    if (dav1d_get_bits(gb, 1))
+                        hdr->loopfilter.mode_ref_deltas.ref_delta[i] =
+                            dav1d_get_sbits(gb, 6);
+                for (int i = 0; i < 2; i++)
+                    if (dav1d_get_bits(gb, 1))
+                        hdr->loopfilter.mode_ref_deltas.mode_delta[i] =
+                            dav1d_get_sbits(gb, 6);
+            }
+        }
+    }
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-lpf: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+
+    // cdef
+    if (!hdr->all_lossless && seqhdr->cdef && !hdr->allow_intrabc) {
+        hdr->cdef.damping = dav1d_get_bits(gb, 2) + 3;
+        hdr->cdef.n_bits = dav1d_get_bits(gb, 2);
+        for (int i = 0; i < (1 << hdr->cdef.n_bits); i++) {
+            hdr->cdef.y_strength[i] = dav1d_get_bits(gb, 6);
+            if (!seqhdr->monochrome)
+                hdr->cdef.uv_strength[i] = dav1d_get_bits(gb, 6);
+        }
+    } else {
+        hdr->cdef.n_bits = 0;
+        hdr->cdef.y_strength[0] = 0;
+        hdr->cdef.uv_strength[0] = 0;
+    }
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-cdef: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+
+    // restoration
+    if ((!hdr->all_lossless || hdr->super_res.enabled) &&
+        seqhdr->restoration && !hdr->allow_intrabc)
+    {
+        hdr->restoration.type[0] = dav1d_get_bits(gb, 2);
+        if (!seqhdr->monochrome) {
+            hdr->restoration.type[1] = dav1d_get_bits(gb, 2);
+            hdr->restoration.type[2] = dav1d_get_bits(gb, 2);
+        } else {
+            hdr->restoration.type[1] =
+            hdr->restoration.type[2] = DAV1D_RESTORATION_NONE;
+        }
+
+        if (hdr->restoration.type[0] || hdr->restoration.type[1] ||
+            hdr->restoration.type[2])
+        {
+            // Log2 of the restoration unit size.
+            hdr->restoration.unit_size[0] = 6 + seqhdr->sb128;
+            if (dav1d_get_bits(gb, 1)) {
+                hdr->restoration.unit_size[0]++;
+                if (!seqhdr->sb128)
+                    hdr->restoration.unit_size[0] += dav1d_get_bits(gb, 1);
+            }
+            hdr->restoration.unit_size[1] = hdr->restoration.unit_size[0];
+            if ((hdr->restoration.type[1] || hdr->restoration.type[2]) &&
+                seqhdr->ss_hor == 1 && seqhdr->ss_ver == 1)
+            {
+                hdr->restoration.unit_size[1] -= dav1d_get_bits(gb, 1);
+            }
+        } else {
+            hdr->restoration.unit_size[0] = 8;
+        }
+    } else {
+        hdr->restoration.type[0] = DAV1D_RESTORATION_NONE;
+        hdr->restoration.type[1] = DAV1D_RESTORATION_NONE;
+        hdr->restoration.type[2] = DAV1D_RESTORATION_NONE;
+    }
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-restoration: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+
+    hdr->txfm_mode = hdr->all_lossless ? DAV1D_TX_4X4_ONLY :
+                     dav1d_get_bits(gb, 1) ? DAV1D_TX_SWITCHABLE : DAV1D_TX_LARGEST;
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-txfmmode: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+    hdr->switchable_comp_refs = IS_INTER_OR_SWITCH(hdr) ? dav1d_get_bits(gb, 1) : 0;
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-refmode: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+    hdr->skip_mode_allowed = 0;
+    if (hdr->switchable_comp_refs && IS_INTER_OR_SWITCH(hdr) && seqhdr->order_hint) {
+        const unsigned poc = hdr->frame_offset;
+        unsigned off_before = 0xFFFFFFFFU;
+        int off_after = -1;
+        int off_before_idx, off_after_idx;
+        for (int i = 0; i < 7; i++) {
+            if (!c->refs[hdr->refidx[i]].p.p.data[0]) goto error;
+            const unsigned refpoc = c->refs[hdr->refidx[i]].p.p.frame_hdr->frame_offset;
+
+            const int diff = get_poc_diff(seqhdr->order_hint_n_bits, refpoc, poc);
+            if (diff > 0) {
+                if (off_after == -1 || get_poc_diff(seqhdr->order_hint_n_bits,
+                                                    off_after, refpoc) > 0)
+                {
+                    off_after = refpoc;
+                    off_after_idx = i;
+                }
+            } else if (diff < 0 && (off_before == 0xFFFFFFFFU ||
+                                    get_poc_diff(seqhdr->order_hint_n_bits,
+                                                 refpoc, off_before) > 0))
+            {
+                off_before = refpoc;
+                off_before_idx = i;
+            }
+        }
+
+        if (off_before != 0xFFFFFFFFU && off_after != -1) {
+            hdr->skip_mode_refs[0] = imin(off_before_idx, off_after_idx);
+            hdr->skip_mode_refs[1] = imax(off_before_idx, off_after_idx);
+            hdr->skip_mode_allowed = 1;
+        } else if (off_before != 0xFFFFFFFFU) {
+            unsigned off_before2 = 0xFFFFFFFFU;
+            int off_before2_idx;
+            for (int i = 0; i < 7; i++) {
+                if (!c->refs[hdr->refidx[i]].p.p.data[0]) goto error;
+                const unsigned refpoc = c->refs[hdr->refidx[i]].p.p.frame_hdr->frame_offset;
+                if (get_poc_diff(seqhdr->order_hint_n_bits,
+                                 refpoc, off_before) < 0) {
+                    if (off_before2 == 0xFFFFFFFFU ||
+                        get_poc_diff(seqhdr->order_hint_n_bits,
+                                     refpoc, off_before2) > 0)
+                    {
+                        off_before2 = refpoc;
+                        off_before2_idx = i;
+                    }
+                }
+            }
+
+            if (off_before2 != 0xFFFFFFFFU) {
+                hdr->skip_mode_refs[0] = imin(off_before_idx, off_before2_idx);
+                hdr->skip_mode_refs[1] = imax(off_before_idx, off_before2_idx);
+                hdr->skip_mode_allowed = 1;
+            }
+        }
+    }
+    hdr->skip_mode_enabled = hdr->skip_mode_allowed ? dav1d_get_bits(gb, 1) : 0;
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-extskip: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+    hdr->warp_motion = !hdr->error_resilient_mode && IS_INTER_OR_SWITCH(hdr) &&
+        seqhdr->warped_motion && dav1d_get_bits(gb, 1);
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-warpmotionbit: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+    hdr->reduced_txtp_set = dav1d_get_bits(gb, 1);
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-reducedtxtpset: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+
+    for (int i = 0; i < 7; i++)
+        hdr->gmv[i] = dav1d_default_wm_params;
+
+    if (IS_INTER_OR_SWITCH(hdr)) {
+        for (int i = 0; i < 7; i++) {
+            hdr->gmv[i].type = !dav1d_get_bits(gb, 1) ? DAV1D_WM_TYPE_IDENTITY :
+                                dav1d_get_bits(gb, 1) ? DAV1D_WM_TYPE_ROT_ZOOM :
+                                dav1d_get_bits(gb, 1) ? DAV1D_WM_TYPE_TRANSLATION :
+                                                  DAV1D_WM_TYPE_AFFINE;
+
+            if (hdr->gmv[i].type == DAV1D_WM_TYPE_IDENTITY) continue;
+
+            const Dav1dWarpedMotionParams *ref_gmv;
+            if (hdr->primary_ref_frame == DAV1D_PRIMARY_REF_NONE) {
+                ref_gmv = &dav1d_default_wm_params;
+            } else {
+                const int pri_ref = hdr->refidx[hdr->primary_ref_frame];
+                if (!c->refs[pri_ref].p.p.frame_hdr) goto error;
+                ref_gmv = &c->refs[pri_ref].p.p.frame_hdr->gmv[i];
+            }
+            int32_t *const mat = hdr->gmv[i].matrix;
+            const int32_t *const ref_mat = ref_gmv->matrix;
+            int bits, shift;
+
+            if (hdr->gmv[i].type >= DAV1D_WM_TYPE_ROT_ZOOM) {
+                mat[2] = (1 << 16) + 2 *
+                    dav1d_get_bits_subexp(gb, (ref_mat[2] - (1 << 16)) >> 1, 12);
+                mat[3] = 2 * dav1d_get_bits_subexp(gb, ref_mat[3] >> 1, 12);
+
+                bits = 12;
+                shift = 10;
+            } else {
+                bits = 9 - !hdr->hp;
+                shift = 13 + !hdr->hp;
+            }
+
+            if (hdr->gmv[i].type == DAV1D_WM_TYPE_AFFINE) {
+                mat[4] = 2 * dav1d_get_bits_subexp(gb, ref_mat[4] >> 1, 12);
+                mat[5] = (1 << 16) + 2 *
+                    dav1d_get_bits_subexp(gb, (ref_mat[5] - (1 << 16)) >> 1, 12);
+            } else {
+                mat[4] = -mat[3];
+                mat[5] = mat[2];
+            }
+
+            mat[0] = dav1d_get_bits_subexp(gb, ref_mat[0] >> shift, bits) * (1 << shift);
+            mat[1] = dav1d_get_bits_subexp(gb, ref_mat[1] >> shift, bits) * (1 << shift);
+        }
+    }
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-gmv: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+
+    hdr->film_grain.present = seqhdr->film_grain_present &&
+                              (hdr->show_frame || hdr->showable_frame) &&
+                              dav1d_get_bits(gb, 1);
+    if (hdr->film_grain.present) {
+        const unsigned seed = dav1d_get_bits(gb, 16);
+        hdr->film_grain.update = hdr->frame_type != DAV1D_FRAME_TYPE_INTER || dav1d_get_bits(gb, 1);
+        if (!hdr->film_grain.update) {
+            const int refidx = dav1d_get_bits(gb, 3);
+            int i;
+            for (i = 0; i < 7; i++)
+                if (hdr->refidx[i] == refidx)
+                    break;
+            if (i == 7 || !c->refs[refidx].p.p.frame_hdr) goto error;
+            hdr->film_grain.data = c->refs[refidx].p.p.frame_hdr->film_grain.data;
+            hdr->film_grain.data.seed = seed;
+        } else {
+            Dav1dFilmGrainData *const fgd = &hdr->film_grain.data;
+            fgd->seed = seed;
+
+            fgd->num_y_points = dav1d_get_bits(gb, 4);
+            if (fgd->num_y_points > 14) goto error;
+            for (int i = 0; i < fgd->num_y_points; i++) {
+                fgd->y_points[i][0] = dav1d_get_bits(gb, 8);
+                if (i && fgd->y_points[i - 1][0] >= fgd->y_points[i][0])
+                    goto error;
+                fgd->y_points[i][1] = dav1d_get_bits(gb, 8);
+            }
+
+            fgd->chroma_scaling_from_luma =
+                !seqhdr->monochrome && dav1d_get_bits(gb, 1);
+            if (seqhdr->monochrome || fgd->chroma_scaling_from_luma ||
+                (seqhdr->ss_ver == 1 && seqhdr->ss_hor == 1 && !fgd->num_y_points))
+            {
+                fgd->num_uv_points[0] = fgd->num_uv_points[1] = 0;
+            } else for (int pl = 0; pl < 2; pl++) {
+                fgd->num_uv_points[pl] = dav1d_get_bits(gb, 4);
+                if (fgd->num_uv_points[pl] > 10) goto error;
+                for (int i = 0; i < fgd->num_uv_points[pl]; i++) {
+                    fgd->uv_points[pl][i][0] = dav1d_get_bits(gb, 8);
+                    if (i && fgd->uv_points[pl][i - 1][0] >= fgd->uv_points[pl][i][0])
+                        goto error;
+                    fgd->uv_points[pl][i][1] = dav1d_get_bits(gb, 8);
+                }
+            }
+
+            if (seqhdr->ss_hor == 1 && seqhdr->ss_ver == 1 &&
+                !!fgd->num_uv_points[0] != !!fgd->num_uv_points[1])
+            {
+                goto error;
+            }
+
+            fgd->scaling_shift = dav1d_get_bits(gb, 2) + 8;
+            fgd->ar_coeff_lag = dav1d_get_bits(gb, 2);
+            const int num_y_pos = 2 * fgd->ar_coeff_lag * (fgd->ar_coeff_lag + 1);
+            if (fgd->num_y_points)
+                for (int i = 0; i < num_y_pos; i++)
+                    fgd->ar_coeffs_y[i] = dav1d_get_bits(gb, 8) - 128;
+            for (int pl = 0; pl < 2; pl++)
+                if (fgd->num_uv_points[pl] || fgd->chroma_scaling_from_luma) {
+                    const int num_uv_pos = num_y_pos + !!fgd->num_y_points;
+                    for (int i = 0; i < num_uv_pos; i++)
+                        fgd->ar_coeffs_uv[pl][i] = dav1d_get_bits(gb, 8) - 128;
+                    if (!fgd->num_y_points)
+                        fgd->ar_coeffs_uv[pl][num_uv_pos] = 0;
+                }
+            fgd->ar_coeff_shift = dav1d_get_bits(gb, 2) + 6;
+            fgd->grain_scale_shift = dav1d_get_bits(gb, 2);
+            for (int pl = 0; pl < 2; pl++)
+                if (fgd->num_uv_points[pl]) {
+                    fgd->uv_mult[pl] = dav1d_get_bits(gb, 8) - 128;
+                    fgd->uv_luma_mult[pl] = dav1d_get_bits(gb, 8) - 128;
+                    fgd->uv_offset[pl] = dav1d_get_bits(gb, 9) - 256;
+                }
+            fgd->overlap_flag = dav1d_get_bits(gb, 1);
+            fgd->clip_to_restricted_range = dav1d_get_bits(gb, 1);
+        }
+    } else {
+        memset(&hdr->film_grain.data, 0, sizeof(hdr->film_grain.data));
+    }
+#if DEBUG_FRAME_HDR
+    printf("HDR: post-filmgrain: off=%td\n",
+           (gb->ptr - init_ptr) * 8 - gb->bits_left);
+#endif
+
+    return 0;
+
+error:
+    dav1d_log(c, "Error parsing frame header\n");
+    return DAV1D_ERR(EINVAL);
+}
+
+static void parse_tile_hdr(Dav1dContext *const c, GetBits *const gb) {
+    const int n_tiles = c->frame_hdr->tiling.cols * c->frame_hdr->tiling.rows;
+    const int have_tile_pos = n_tiles > 1 ? dav1d_get_bits(gb, 1) : 0;
+
+    if (have_tile_pos) {
+        const int n_bits = c->frame_hdr->tiling.log2_cols +
+                           c->frame_hdr->tiling.log2_rows;
+        c->tile[c->n_tile_data].start = dav1d_get_bits(gb, n_bits);
+        c->tile[c->n_tile_data].end = dav1d_get_bits(gb, n_bits);
+    } else {
+        c->tile[c->n_tile_data].start = 0;
+        c->tile[c->n_tile_data].end = n_tiles - 1;
+    }
+}
+
+// Check that we haven't read more than obu_len bytes from the buffer
+// since init_bit_pos.
+static int check_for_overrun(Dav1dContext *const c, GetBits *const gb,
+                             const unsigned init_bit_pos,
+                             const unsigned obu_len)
+{
+    // Make sure we haven't actually read past the end of the gb buffer
+    if (gb->error) {
+        dav1d_log(c, "Overrun in OBU bit buffer\n");
+        return 1;
+    }
+
+    const unsigned pos = dav1d_get_bits_pos(gb);
+
+    // We assume that init_bit_pos was the bit position of the buffer
+    // at some point in the past, so cannot be smaller than pos.
+    assert (init_bit_pos <= pos);
+
+    if (pos - init_bit_pos > 8 * obu_len) {
+        dav1d_log(c, "Overrun in OBU bit buffer into next OBU\n");
+        return 1;
+    }
+
+    return 0;
+}
+
+int dav1d_parse_obus(Dav1dContext *const c, Dav1dData *const in, const int global) {
+    GetBits gb;
+    int res;
+
+    dav1d_init_get_bits(&gb, in->data, in->sz);
+
+    // obu header
+    dav1d_get_bits(&gb, 1); // obu_forbidden_bit
+    const enum Dav1dObuType type = dav1d_get_bits(&gb, 4);
+    const int has_extension = dav1d_get_bits(&gb, 1);
+    const int has_length_field = dav1d_get_bits(&gb, 1);
+    dav1d_get_bits(&gb, 1); // reserved
+
+    int temporal_id = 0, spatial_id = 0;
+    if (has_extension) {
+        temporal_id = dav1d_get_bits(&gb, 3);
+        spatial_id = dav1d_get_bits(&gb, 2);
+        dav1d_get_bits(&gb, 3); // reserved
+    }
+
+    // obu length field
+    const unsigned len = has_length_field ?
+        dav1d_get_uleb128(&gb) : (unsigned) in->sz - 1 - has_extension;
+    if (gb.error) goto error;
+
+    const unsigned init_bit_pos = dav1d_get_bits_pos(&gb);
+    const unsigned init_byte_pos = init_bit_pos >> 3;
+
+    // We must have read a whole number of bytes at this point (1 byte
+    // for the header and whole bytes at a time when reading the
+    // leb128 length field).
+    assert((init_bit_pos & 7) == 0);
+
+    // We also know that we haven't tried to read more than in->sz
+    // bytes yet (otherwise the error flag would have been set by the
+    // code in getbits.c)
+    assert(in->sz >= init_byte_pos);
+
+    // Make sure that there are enough bits left in the buffer for the
+    // rest of the OBU.
+    if (len > in->sz - init_byte_pos) goto error;
+
+    // skip obu not belonging to the selected temporal/spatial layer
+    if (type != DAV1D_OBU_SEQ_HDR && type != DAV1D_OBU_TD &&
+        has_extension && c->operating_point_idc != 0)
+    {
+        const int in_temporal_layer = (c->operating_point_idc >> temporal_id) & 1;
+        const int in_spatial_layer = (c->operating_point_idc >> (spatial_id + 8)) & 1;
+        if (!in_temporal_layer || !in_spatial_layer)
+            return len + init_byte_pos;
+    }
+
+    switch (type) {
+    case DAV1D_OBU_SEQ_HDR: {
+        Dav1dRef *ref = dav1d_ref_create_using_pool(c->seq_hdr_pool,
+                                                    sizeof(Dav1dSequenceHeader));
+        if (!ref) return DAV1D_ERR(ENOMEM);
+        Dav1dSequenceHeader *seq_hdr = ref->data;
+        memset(seq_hdr, 0, sizeof(*seq_hdr));
+        if ((res = parse_seq_hdr(c, &gb, seq_hdr)) < 0) {
+            dav1d_ref_dec(&ref);
+            goto error;
+        }
+        if (check_for_overrun(c, &gb, init_bit_pos, len)) {
+            dav1d_ref_dec(&ref);
+            goto error;
+        }
+        // If we have read a sequence header which is different from
+        // the old one, this is a new video sequence and can't use any
+        // previous state. Free that state.
+
+        if (!c->seq_hdr) {
+            c->frame_hdr = NULL;
+            c->frame_flags |= PICTURE_FLAG_NEW_SEQUENCE;
+        // see 7.5, operating_parameter_info is allowed to change in
+        // sequence headers of a single sequence
+        } else if (memcmp(seq_hdr, c->seq_hdr, offsetof(Dav1dSequenceHeader, operating_parameter_info))) {
+            c->frame_hdr = NULL;
+            c->mastering_display = NULL;
+            c->content_light = NULL;
+            dav1d_ref_dec(&c->mastering_display_ref);
+            dav1d_ref_dec(&c->content_light_ref);
+            for (int i = 0; i < 8; i++) {
+                if (c->refs[i].p.p.data[0])
+                    dav1d_thread_picture_unref(&c->refs[i].p);
+                dav1d_ref_dec(&c->refs[i].segmap);
+                dav1d_ref_dec(&c->refs[i].refmvs);
+                dav1d_cdf_thread_unref(&c->cdf[i]);
+            }
+            c->frame_flags |= PICTURE_FLAG_NEW_SEQUENCE;
+        // If operating_parameter_info changed, signal it
+        } else if (memcmp(seq_hdr->operating_parameter_info, c->seq_hdr->operating_parameter_info,
+                          sizeof(seq_hdr->operating_parameter_info)))
+        {
+            c->frame_flags |= PICTURE_FLAG_NEW_OP_PARAMS_INFO;
+        }
+        dav1d_ref_dec(&c->seq_hdr_ref);
+        c->seq_hdr_ref = ref;
+        c->seq_hdr = seq_hdr;
+        break;
+    }
+    case DAV1D_OBU_REDUNDANT_FRAME_HDR:
+        if (c->frame_hdr) break;
+        // fall-through
+    case DAV1D_OBU_FRAME:
+    case DAV1D_OBU_FRAME_HDR:
+        if (global) break;
+        if (!c->seq_hdr) goto error;
+        if (!c->frame_hdr_ref) {
+            c->frame_hdr_ref = dav1d_ref_create_using_pool(c->frame_hdr_pool,
+                                                           sizeof(Dav1dFrameHeader));
+            if (!c->frame_hdr_ref) return DAV1D_ERR(ENOMEM);
+        }
+#ifndef NDEBUG
+        // ensure that the reference is writable
+        assert(dav1d_ref_is_writable(c->frame_hdr_ref));
+#endif
+        c->frame_hdr = c->frame_hdr_ref->data;
+        memset(c->frame_hdr, 0, sizeof(*c->frame_hdr));
+        c->frame_hdr->temporal_id = temporal_id;
+        c->frame_hdr->spatial_id = spatial_id;
+        if ((res = parse_frame_hdr(c, &gb)) < 0) {
+            c->frame_hdr = NULL;
+            goto error;
+        }
+        for (int n = 0; n < c->n_tile_data; n++)
+            dav1d_data_unref_internal(&c->tile[n].data);
+        c->n_tile_data = 0;
+        c->n_tiles = 0;
+        if (type != DAV1D_OBU_FRAME) {
+            // This is actually a frame header OBU so read the
+            // trailing bit and check for overrun.
+            dav1d_get_bits(&gb, 1);
+            if (check_for_overrun(c, &gb, init_bit_pos, len)) {
+                c->frame_hdr = NULL;
+                goto error;
+            }
+        }
+
+        if (c->frame_size_limit && (int64_t)c->frame_hdr->width[1] *
+            c->frame_hdr->height > c->frame_size_limit)
+        {
+            dav1d_log(c, "Frame size %dx%d exceeds limit %u\n", c->frame_hdr->width[1],
+                      c->frame_hdr->height, c->frame_size_limit);
+            c->frame_hdr = NULL;
+            return DAV1D_ERR(ERANGE);
+        }
+
+        if (type != DAV1D_OBU_FRAME)
+            break;
+        // OBU_FRAMEs shouldn't be signaled with show_existing_frame
+        if (c->frame_hdr->show_existing_frame) {
+            c->frame_hdr = NULL;
+            goto error;
+        }
+
+        // This is the frame header at the start of a frame OBU.
+        // There's no trailing bit at the end to skip, but we do need
+        // to align to the next byte.
+        dav1d_bytealign_get_bits(&gb);
+        // fall-through
+    case DAV1D_OBU_TILE_GRP: {
+        if (global) break;
+        if (!c->frame_hdr) goto error;
+        if (c->n_tile_data_alloc < c->n_tile_data + 1) {
+            if ((c->n_tile_data + 1) > INT_MAX / (int)sizeof(*c->tile)) goto error;
+            struct Dav1dTileGroup *tile = realloc(c->tile, (c->n_tile_data + 1) * sizeof(*c->tile));
+            if (!tile) goto error;
+            c->tile = tile;
+            memset(c->tile + c->n_tile_data, 0, sizeof(*c->tile));
+            c->n_tile_data_alloc = c->n_tile_data + 1;
+        }
+        parse_tile_hdr(c, &gb);
+        // Align to the next byte boundary and check for overrun.
+        dav1d_bytealign_get_bits(&gb);
+        if (check_for_overrun(c, &gb, init_bit_pos, len))
+            goto error;
+        // The current bit position is a multiple of 8 (because we
+        // just aligned it) and less than 8*pkt_bytelen because
+        // otherwise the overrun check would have fired.
+        const unsigned pkt_bytelen = init_byte_pos + len;
+        const unsigned bit_pos = dav1d_get_bits_pos(&gb);
+        assert((bit_pos & 7) == 0);
+        assert(pkt_bytelen >= (bit_pos >> 3));
+        dav1d_data_ref(&c->tile[c->n_tile_data].data, in);
+        c->tile[c->n_tile_data].data.data += bit_pos >> 3;
+        c->tile[c->n_tile_data].data.sz = pkt_bytelen - (bit_pos >> 3);
+        // ensure tile groups are in order and sane, see 6.10.1
+        if (c->tile[c->n_tile_data].start > c->tile[c->n_tile_data].end ||
+            c->tile[c->n_tile_data].start != c->n_tiles)
+        {
+            for (int i = 0; i <= c->n_tile_data; i++)
+                dav1d_data_unref_internal(&c->tile[i].data);
+            c->n_tile_data = 0;
+            c->n_tiles = 0;
+            goto error;
+        }
+        c->n_tiles += 1 + c->tile[c->n_tile_data].end -
+                          c->tile[c->n_tile_data].start;
+        c->n_tile_data++;
+        break;
+    }
+    case DAV1D_OBU_METADATA: {
+#define DEBUG_OBU_METADATA 0
+#if DEBUG_OBU_METADATA
+        const uint8_t *const init_ptr = gb.ptr;
+#endif
+        // obu metadta type field
+        const enum ObuMetaType meta_type = dav1d_get_uleb128(&gb);
+        const int meta_type_len = (dav1d_get_bits_pos(&gb) - init_bit_pos) >> 3;
+        if (gb.error) goto error;
+
+        switch (meta_type) {
+        case OBU_META_HDR_CLL: {
+            Dav1dRef *ref = dav1d_ref_create(sizeof(Dav1dContentLightLevel));
+            if (!ref) return DAV1D_ERR(ENOMEM);
+            Dav1dContentLightLevel *const content_light = ref->data;
+
+            content_light->max_content_light_level = dav1d_get_bits(&gb, 16);
+#if DEBUG_OBU_METADATA
+            printf("CLLOBU: max-content-light-level: %d [off=%td]\n",
+                   content_light->max_content_light_level,
+                   (gb.ptr - init_ptr) * 8 - gb.bits_left);
+#endif
+            content_light->max_frame_average_light_level = dav1d_get_bits(&gb, 16);
+#if DEBUG_OBU_METADATA
+            printf("CLLOBU: max-frame-average-light-level: %d [off=%td]\n",
+                   content_light->max_frame_average_light_level,
+                   (gb.ptr - init_ptr) * 8 - gb.bits_left);
+#endif
+
+            // Skip the trailing bit, align to the next byte boundary and check for overrun.
+            dav1d_get_bits(&gb, 1);
+            dav1d_bytealign_get_bits(&gb);
+            if (check_for_overrun(c, &gb, init_bit_pos, len)) {
+                dav1d_ref_dec(&ref);
+                goto error;
+            }
+
+            dav1d_ref_dec(&c->content_light_ref);
+            c->content_light = content_light;
+            c->content_light_ref = ref;
+            break;
+        }
+        case OBU_META_HDR_MDCV: {
+            Dav1dRef *ref = dav1d_ref_create(sizeof(Dav1dMasteringDisplay));
+            if (!ref) return DAV1D_ERR(ENOMEM);
+            Dav1dMasteringDisplay *const mastering_display = ref->data;
+
+            for (int i = 0; i < 3; i++) {
+                mastering_display->primaries[i][0] = dav1d_get_bits(&gb, 16);
+                mastering_display->primaries[i][1] = dav1d_get_bits(&gb, 16);
+#if DEBUG_OBU_METADATA
+                printf("MDCVOBU: primaries[%d]: (%d, %d) [off=%td]\n", i,
+                       mastering_display->primaries[i][0],
+                       mastering_display->primaries[i][1],
+                       (gb.ptr - init_ptr) * 8 - gb.bits_left);
+#endif
+            }
+            mastering_display->white_point[0] = dav1d_get_bits(&gb, 16);
+#if DEBUG_OBU_METADATA
+            printf("MDCVOBU: white-point-x: %d [off=%td]\n",
+                   mastering_display->white_point[0],
+                   (gb.ptr - init_ptr) * 8 - gb.bits_left);
+#endif
+            mastering_display->white_point[1] = dav1d_get_bits(&gb, 16);
+#if DEBUG_OBU_METADATA
+            printf("MDCVOBU: white-point-y: %d [off=%td]\n",
+                   mastering_display->white_point[1],
+                   (gb.ptr - init_ptr) * 8 - gb.bits_left);
+#endif
+            mastering_display->max_luminance = dav1d_get_bits(&gb, 32);
+#if DEBUG_OBU_METADATA
+            printf("MDCVOBU: max-luminance: %d [off=%td]\n",
+                   mastering_display->max_luminance,
+                   (gb.ptr - init_ptr) * 8 - gb.bits_left);
+#endif
+            mastering_display->min_luminance = dav1d_get_bits(&gb, 32);
+#if DEBUG_OBU_METADATA
+            printf("MDCVOBU: min-luminance: %d [off=%td]\n",
+                   mastering_display->min_luminance,
+                   (gb.ptr - init_ptr) * 8 - gb.bits_left);
+#endif
+            // Skip the trailing bit, align to the next byte boundary and check for overrun.
+            dav1d_get_bits(&gb, 1);
+            dav1d_bytealign_get_bits(&gb);
+            if (check_for_overrun(c, &gb, init_bit_pos, len)) {
+                dav1d_ref_dec(&ref);
+                goto error;
+            }
+
+            dav1d_ref_dec(&c->mastering_display_ref);
+            c->mastering_display = mastering_display;
+            c->mastering_display_ref = ref;
+            break;
+        }
+        case OBU_META_ITUT_T35: {
+            int payload_size = len;
+            // Don't take into account all the trailing bits for payload_size
+            while (payload_size > 0 && !in->data[init_byte_pos + payload_size - 1])
+                payload_size--; // trailing_zero_bit x 8
+            payload_size--; // trailing_one_bit + trailing_zero_bit x 7
+
+            // Don't take into account meta_type bytes
+            payload_size -= meta_type_len;
+
+            int country_code_extension_byte = 0;
+            const int country_code = dav1d_get_bits(&gb, 8);
+            payload_size--;
+            if (country_code == 0xFF) {
+                country_code_extension_byte = dav1d_get_bits(&gb, 8);
+                payload_size--;
+            }
+
+            if (payload_size <= 0) {
+                dav1d_log(c, "Malformed ITU-T T.35 metadata message format\n");
+                break;
+            }
+
+            Dav1dRef *ref = dav1d_ref_create(sizeof(Dav1dITUTT35) + payload_size * sizeof(uint8_t));
+            if (!ref) return DAV1D_ERR(ENOMEM);
+            Dav1dITUTT35 *const itut_t35_metadata = ref->data;
+
+            // We need our public headers to be C++ compatible, so payload can't be
+            // a flexible array member
+            itut_t35_metadata->payload = (uint8_t *) &itut_t35_metadata[1];
+            itut_t35_metadata->country_code = country_code;
+            itut_t35_metadata->country_code_extension_byte = country_code_extension_byte;
+            for (int i = 0; i < payload_size; i++)
+                itut_t35_metadata->payload[i] = dav1d_get_bits(&gb, 8);
+            itut_t35_metadata->payload_size = payload_size;
+
+            dav1d_ref_dec(&c->itut_t35_ref);
+            c->itut_t35 = itut_t35_metadata;
+            c->itut_t35_ref = ref;
+            break;
+        }
+        case OBU_META_SCALABILITY:
+        case OBU_META_TIMECODE:
+            // ignore metadata OBUs we don't care about
+            break;
+        default:
+            // print a warning but don't fail for unknown types
+            dav1d_log(c, "Unknown Metadata OBU type %d\n", meta_type);
+            break;
+        }
+
+        break;
+    }
+    case DAV1D_OBU_TD:
+        c->frame_flags |= PICTURE_FLAG_NEW_TEMPORAL_UNIT;
+        break;
+    case DAV1D_OBU_PADDING:
+        // ignore OBUs we don't care about
+        break;
+    default:
+        // print a warning but don't fail for unknown types
+        dav1d_log(c, "Unknown OBU type %d of size %u\n", type, len);
+        break;
+    }
+
+    if (c->seq_hdr && c->frame_hdr) {
+        if (c->frame_hdr->show_existing_frame) {
+            if (!c->refs[c->frame_hdr->existing_frame_idx].p.p.data[0]) goto error;
+            if (c->strict_std_compliance &&
+                !c->refs[c->frame_hdr->existing_frame_idx].p.showable)
+            {
+                goto error;
+            }
+            if (c->n_fc == 1) {
+                dav1d_thread_picture_ref(&c->out,
+                                         &c->refs[c->frame_hdr->existing_frame_idx].p);
+                dav1d_data_props_copy(&c->out.p.m, &in->m);
+                c->event_flags |= dav1d_picture_get_event_flags(&c->refs[c->frame_hdr->existing_frame_idx].p);
+            } else {
+                pthread_mutex_lock(&c->task_thread.lock);
+                // need to append this to the frame output queue
+                const unsigned next = c->frame_thread.next++;
+                if (c->frame_thread.next == c->n_fc)
+                    c->frame_thread.next = 0;
+
+                Dav1dFrameContext *const f = &c->fc[next];
+                while (f->n_tile_data > 0)
+                    pthread_cond_wait(&f->task_thread.cond,
+                                      &f->task_thread.ttd->lock);
+                Dav1dThreadPicture *const out_delayed =
+                    &c->frame_thread.out_delayed[next];
+                if (out_delayed->p.data[0] || atomic_load(&f->task_thread.error)) {
+                    unsigned first = atomic_load(&c->task_thread.first);
+                    if (first + 1U < c->n_fc)
+                        atomic_fetch_add(&c->task_thread.first, 1U);
+                    else
+                        atomic_store(&c->task_thread.first, 0);
+                    atomic_compare_exchange_strong(&c->task_thread.reset_task_cur,
+                                                   &first, UINT_MAX);
+                    if (c->task_thread.cur && c->task_thread.cur < c->n_fc)
+                        c->task_thread.cur--;
+                }
+                const int error = f->task_thread.retval;
+                if (error) {
+                    c->cached_error = error;
+                    f->task_thread.retval = 0;
+                    dav1d_data_props_copy(&c->cached_error_props, &out_delayed->p.m);
+                    dav1d_thread_picture_unref(out_delayed);
+                } else if (out_delayed->p.data[0]) {
+                    const unsigned progress = atomic_load_explicit(&out_delayed->progress[1],
+                                                                   memory_order_relaxed);
+                    if ((out_delayed->visible || c->output_invisible_frames) &&
+                        progress != FRAME_ERROR)
+                    {
+                        dav1d_thread_picture_ref(&c->out, out_delayed);
+                        c->event_flags |= dav1d_picture_get_event_flags(out_delayed);
+                    }
+                    dav1d_thread_picture_unref(out_delayed);
+                }
+                dav1d_thread_picture_ref(out_delayed,
+                                         &c->refs[c->frame_hdr->existing_frame_idx].p);
+                out_delayed->visible = 1;
+                dav1d_data_props_copy(&out_delayed->p.m, &in->m);
+                pthread_mutex_unlock(&c->task_thread.lock);
+            }
+            if (c->refs[c->frame_hdr->existing_frame_idx].p.p.frame_hdr->frame_type == DAV1D_FRAME_TYPE_KEY) {
+                const int r = c->frame_hdr->existing_frame_idx;
+                c->refs[r].p.showable = 0;
+                for (int i = 0; i < 8; i++) {
+                    if (i == r) continue;
+
+                    if (c->refs[i].p.p.data[0])
+                        dav1d_thread_picture_unref(&c->refs[i].p);
+                    dav1d_thread_picture_ref(&c->refs[i].p, &c->refs[r].p);
+
+                    dav1d_cdf_thread_unref(&c->cdf[i]);
+                    dav1d_cdf_thread_ref(&c->cdf[i], &c->cdf[r]);
+
+                    dav1d_ref_dec(&c->refs[i].segmap);
+                    c->refs[i].segmap = c->refs[r].segmap;
+                    if (c->refs[r].segmap)
+                        dav1d_ref_inc(c->refs[r].segmap);
+                    dav1d_ref_dec(&c->refs[i].refmvs);
+                }
+            }
+            c->frame_hdr = NULL;
+        } else if (c->n_tiles == c->frame_hdr->tiling.cols * c->frame_hdr->tiling.rows) {
+            if (!c->n_tile_data)
+                goto error;
+            if ((res = dav1d_submit_frame(c)) < 0)
+                return res;
+            assert(!c->n_tile_data);
+            c->frame_hdr = NULL;
+            c->n_tiles = 0;
+        }
+    }
+
+    return len + init_byte_pos;
+
+error:
+    dav1d_data_props_copy(&c->cached_error_props, &in->m);
+    dav1d_log(c, "Error parsing OBU data\n");
+    return DAV1D_ERR(EINVAL);
+}