1 files changed, 325 insertions, 0 deletions
diff --git a/audio/decode/ad_lavc.c b/audio/decode/ad_lavc.c
new file mode 100644
index 0000000..08b789a
--- /dev/null
+++ b/audio/decode/ad_lavc.c
@@ -0,0 +1,325 @@
+/*
+ * This file is part of mpv.
+ *
+ * mpv is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * mpv is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <assert.h>
+
+#include <libavcodec/avcodec.h>
+#include <libavutil/opt.h>
+#include <libavutil/common.h>
+#include <libavutil/intreadwrite.h>
+
+#include "config.h"
+
+#include "mpv_talloc.h"
+#include "audio/aframe.h"
+#include "audio/chmap_avchannel.h"
+#include "audio/fmt-conversion.h"
+#include "common/av_common.h"
+#include "common/codecs.h"
+#include "common/global.h"
+#include "common/msg.h"
+#include "demux/packet.h"
+#include "demux/stheader.h"
+#include "filters/f_decoder_wrapper.h"
+#include "filters/filter_internal.h"
+#include "options/m_config.h"
+#include "options/options.h"
+
+struct priv {
+    AVCodecContext *avctx;
+    AVFrame *avframe;
+    AVPacket *avpkt;
+    struct mp_chmap force_channel_map;
+    uint32_t skip_samples, trim_samples;
+    bool preroll_done;
+    double next_pts;
+    AVRational codec_timebase;
+    struct lavc_state state;
+
+    struct mp_decoder public;
+};
+
+#define OPT_BASE_STRUCT struct ad_lavc_params
+struct ad_lavc_params {
+    float ac3drc;
+    bool downmix;
+    int threads;
+    char **avopts;
+};
+
+const struct m_sub_options ad_lavc_conf = {
+    .opts = (const m_option_t[]) {
+        {"ac3drc", OPT_FLOAT(ac3drc), M_RANGE(0, 6)},
+        {"downmix", OPT_BOOL(downmix)},
+        {"threads", OPT_INT(threads), M_RANGE(0, 16)},
+        {"o", OPT_KEYVALUELIST(avopts)},
+        {0}
+    },
+    .size = sizeof(struct ad_lavc_params),
+    .defaults = &(const struct ad_lavc_params){
+        .ac3drc = 0,
+        .threads = 1,
+    },
+};
+
+static bool init(struct mp_filter *da, struct mp_codec_params *codec,
+                 const char *decoder)
+{
+    struct priv *ctx = da->priv;
+    struct MPOpts *mpopts = mp_get_config_group(ctx, da->global, &mp_opt_root);
+    struct ad_lavc_params *opts =
+        mp_get_config_group(ctx, da->global, &ad_lavc_conf);
+    AVCodecContext *lavc_context;
+    const AVCodec *lavc_codec;
+
+    ctx->codec_timebase = mp_get_codec_timebase(codec);
+
+    if (codec->force_channels)
+        ctx->force_channel_map = codec->channels;
+
+    lavc_codec = avcodec_find_decoder_by_name(decoder);
+    if (!lavc_codec) {
+        MP_ERR(da, "Cannot find codec '%s' in libavcodec...\n", decoder);
+        return false;
+    }
+
+    lavc_context = avcodec_alloc_context3(lavc_codec);
+    ctx->avctx = lavc_context;
+    ctx->avframe = av_frame_alloc();
+    ctx->avpkt = av_packet_alloc();
+    MP_HANDLE_OOM(ctx->avctx && ctx->avframe && ctx->avpkt);
+    lavc_context->codec_type = AVMEDIA_TYPE_AUDIO;
+    lavc_context->codec_id = lavc_codec->id;
+    lavc_context->pkt_timebase = ctx->codec_timebase;
+
+    if (opts->downmix && mpopts->audio_output_channels.num_chmaps == 1) {
+        const struct mp_chmap *requested_layout =
+            &mpopts->audio_output_channels.chmaps[0];
+#if !HAVE_AV_CHANNEL_LAYOUT
+        lavc_context->request_channel_layout =
+            mp_chmap_to_lavc(requested_layout);
+#else
+        AVChannelLayout av_layout = { 0 };
+        mp_chmap_to_av_layout(&av_layout, requested_layout);
+
+        // Always try to set requested output layout - currently only something
+        // supported by AC3, MLP/TrueHD, DTS and the fdk-aac wrapper.
+        av_opt_set_chlayout(lavc_context, "downmix", &av_layout,
+                            AV_OPT_SEARCH_CHILDREN);
+
+        av_channel_layout_uninit(&av_layout);
+#endif
+    }
+
+    // Always try to set - option only exists for AC3 at the moment
+    av_opt_set_double(lavc_context, "drc_scale", opts->ac3drc,
+                      AV_OPT_SEARCH_CHILDREN);
+
+    // Let decoder add AV_FRAME_DATA_SKIP_SAMPLES.
+    av_opt_set(lavc_context, "flags2", "+skip_manual", AV_OPT_SEARCH_CHILDREN);
+
+    mp_set_avopts(da->log, lavc_context, opts->avopts);
+
+    if (mp_set_avctx_codec_headers(lavc_context, codec) < 0) {
+        MP_ERR(da, "Could not set decoder parameters.\n");
+        return false;
+    }
+
+    mp_set_avcodec_threads(da->log, lavc_context, opts->threads);
+
+    /* open it */
+    if (avcodec_open2(lavc_context, lavc_codec, NULL) < 0) {
+        MP_ERR(da, "Could not open codec.\n");
+        return false;
+    }
+
+    ctx->next_pts = MP_NOPTS_VALUE;
+
+    return true;
+}
+
+static void destroy(struct mp_filter *da)
+{
+    struct priv *ctx = da->priv;
+
+    avcodec_free_context(&ctx->avctx);
+    av_frame_free(&ctx->avframe);
+    mp_free_av_packet(&ctx->avpkt);
+}
+
+static void reset(struct mp_filter *da)
+{
+    struct priv *ctx = da->priv;
+
+    avcodec_flush_buffers(ctx->avctx);
+    ctx->skip_samples = 0;
+    ctx->trim_samples = 0;
+    ctx->preroll_done = false;
+    ctx->next_pts = MP_NOPTS_VALUE;
+    ctx->state = (struct lavc_state){0};
+}
+
+static int send_packet(struct mp_filter *da, struct demux_packet *mpkt)
+{
+    struct priv *priv = da->priv;
+    AVCodecContext *avctx = priv->avctx;
+
+    // If the decoder discards the timestamp for some reason, we use the
+    // interpolated PTS. Initialize it so that it works for the initial
+    // packet as well.
+    if (mpkt && priv->next_pts == MP_NOPTS_VALUE)
+        priv->next_pts = mpkt->pts;
+
+    mp_set_av_packet(priv->avpkt, mpkt, &priv->codec_timebase);
+
+    int ret = avcodec_send_packet(avctx, mpkt ? priv->avpkt : NULL);
+    if (ret < 0)
+        MP_ERR(da, "Error decoding audio.\n");
+    return ret;
+}
+
+static int receive_frame(struct mp_filter *da, struct mp_frame *out)
+{
+    struct priv *priv = da->priv;
+    AVCodecContext *avctx = priv->avctx;
+
+    int ret = avcodec_receive_frame(avctx, priv->avframe);
+
+    if (ret == AVERROR_EOF) {
+        // If flushing was initialized earlier and has ended now, make it start
+        // over in case we get new packets at some point in the future.
+        // (Dont' reset the filter itself, we want to keep other state.)
+        avcodec_flush_buffers(priv->avctx);
+        return ret;
+    } else if (ret < 0 && ret != AVERROR(EAGAIN)) {
+        MP_ERR(da, "Error decoding audio.\n");
+    }
+
+    if (priv->avframe->flags & AV_FRAME_FLAG_DISCARD)
+        av_frame_unref(priv->avframe);
+
+    if (!priv->avframe->buf[0])
+        return ret;
+
+    double out_pts = mp_pts_from_av(priv->avframe->pts, &priv->codec_timebase);
+
+    struct mp_aframe *mpframe = mp_aframe_from_avframe(priv->avframe);
+    if (!mpframe) {
+        MP_ERR(da, "Converting libavcodec frame to mpv frame failed.\n");
+        return ret;
+    }
+
+    if (priv->force_channel_map.num)
+        mp_aframe_set_chmap(mpframe, &priv->force_channel_map);
+
+    if (out_pts == MP_NOPTS_VALUE)
+        out_pts = priv->next_pts;
+    mp_aframe_set_pts(mpframe, out_pts);
+
+    priv->next_pts = mp_aframe_end_pts(mpframe);
+
+    AVFrameSideData *sd =
+        av_frame_get_side_data(priv->avframe, AV_FRAME_DATA_SKIP_SAMPLES);
+    if (sd && sd->size >= 10) {
+        char *d = sd->data;
+        priv->skip_samples += AV_RL32(d + 0);
+        priv->trim_samples += AV_RL32(d + 4);
+    }
+
+    if (!priv->preroll_done) {
+        // Skip only if this isn't already handled by AV_FRAME_DATA_SKIP_SAMPLES.
+        if (!priv->skip_samples)
+            priv->skip_samples = avctx->delay;
+        priv->preroll_done = true;
+    }
+
+    uint32_t skip = MPMIN(priv->skip_samples, mp_aframe_get_size(mpframe));
+    if (skip) {
+        mp_aframe_skip_samples(mpframe, skip);
+        priv->skip_samples -= skip;
+    }
+    uint32_t trim = MPMIN(priv->trim_samples, mp_aframe_get_size(mpframe));
+    if (trim) {
+        mp_aframe_set_size(mpframe, mp_aframe_get_size(mpframe) - trim);
+        priv->trim_samples -= trim;
+    }
+
+    // Strip possibly bogus float values like Infinity, NaN, denormalized
+    mp_aframe_sanitize_float(mpframe);
+
+    if (mp_aframe_get_size(mpframe) > 0) {
+        *out = MAKE_FRAME(MP_FRAME_AUDIO, mpframe);
+    } else {
+        talloc_free(mpframe);
+    }
+
+    av_frame_unref(priv->avframe);
+
+    return ret;
+}
+
+static void process(struct mp_filter *ad)
+{
+    struct priv *priv = ad->priv;
+
+    lavc_process(ad, &priv->state, send_packet, receive_frame);
+}
+
+static const struct mp_filter_info ad_lavc_filter = {
+    .name = "ad_lavc",
+    .priv_size = sizeof(struct priv),
+    .process = process,
+    .reset = reset,
+    .destroy = destroy,
+};
+
+static struct mp_decoder *create(struct mp_filter *parent,
+                                 struct mp_codec_params *codec,
+                                 const char *decoder)
+{
+    struct mp_filter *da = mp_filter_create(parent, &ad_lavc_filter);
+    if (!da)
+        return NULL;
+
+    mp_filter_add_pin(da, MP_PIN_IN, "in");
+    mp_filter_add_pin(da, MP_PIN_OUT, "out");
+
+    da->log = mp_log_new(da, parent->log, NULL);
+
+    struct priv *priv = da->priv;
+    priv->public.f = da;
+
+    if (!init(da, codec, decoder)) {
+        talloc_free(da);
+        return NULL;
+    }
+    return &priv->public;
+}
+
+static void add_decoders(struct mp_decoder_list *list)
+{
+    mp_add_lavc_decoders(list, AVMEDIA_TYPE_AUDIO);
+}
+
+const struct mp_decoder_fns ad_lavc = {
+    .create = create,
+    .add_decoders = add_decoders,
+};