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path: root/drivers/media/pci/tw5864/tw5864-h264.c
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Diffstat (limited to 'drivers/media/pci/tw5864/tw5864-h264.c')
-rw-r--r--drivers/media/pci/tw5864/tw5864-h264.c250
1 files changed, 250 insertions, 0 deletions
diff --git a/drivers/media/pci/tw5864/tw5864-h264.c b/drivers/media/pci/tw5864/tw5864-h264.c
new file mode 100644
index 0000000000..608798af67
--- /dev/null
+++ b/drivers/media/pci/tw5864/tw5864-h264.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TW5864 driver - H.264 headers generation functions
+ *
+ * Copyright (C) 2016 Bluecherry, LLC <maintainers@bluecherrydvr.com>
+ */
+
+#include <linux/log2.h>
+
+#include "tw5864.h"
+
+static u8 marker[] = { 0x00, 0x00, 0x00, 0x01 };
+
+/*
+ * Exponential-Golomb coding functions
+ *
+ * These functions are used for generation of H.264 bitstream headers.
+ *
+ * This code is derived from tw5864 reference driver by manufacturers, which
+ * itself apparently was derived from x264 project.
+ */
+
+/* Bitstream writing context */
+struct bs {
+ u8 *buf; /* pointer to buffer beginning */
+ u8 *buf_end; /* pointer to buffer end */
+ u8 *ptr; /* pointer to current byte in buffer */
+ unsigned int bits_left; /* number of available bits in current byte */
+};
+
+static void bs_init(struct bs *s, void *buf, int size)
+{
+ s->buf = buf;
+ s->ptr = buf;
+ s->buf_end = s->ptr + size;
+ s->bits_left = 8;
+}
+
+static int bs_len(struct bs *s)
+{
+ return s->ptr - s->buf;
+}
+
+static void bs_write(struct bs *s, int count, u32 bits)
+{
+ if (s->ptr >= s->buf_end - 4)
+ return;
+ while (count > 0) {
+ if (count < 32)
+ bits &= (1 << count) - 1;
+ if (count < s->bits_left) {
+ *s->ptr = (*s->ptr << count) | bits;
+ s->bits_left -= count;
+ break;
+ }
+ *s->ptr = (*s->ptr << s->bits_left) |
+ (bits >> (count - s->bits_left));
+ count -= s->bits_left;
+ s->ptr++;
+ s->bits_left = 8;
+ }
+}
+
+static void bs_write1(struct bs *s, u32 bit)
+{
+ if (s->ptr < s->buf_end) {
+ *s->ptr <<= 1;
+ *s->ptr |= bit;
+ s->bits_left--;
+ if (s->bits_left == 0) {
+ s->ptr++;
+ s->bits_left = 8;
+ }
+ }
+}
+
+static void bs_write_ue(struct bs *s, u32 val)
+{
+ if (val == 0) {
+ bs_write1(s, 1);
+ } else {
+ val++;
+ bs_write(s, 2 * fls(val) - 1, val);
+ }
+}
+
+static void bs_write_se(struct bs *s, int val)
+{
+ bs_write_ue(s, val <= 0 ? -val * 2 : val * 2 - 1);
+}
+
+static void bs_rbsp_trailing(struct bs *s)
+{
+ bs_write1(s, 1);
+ if (s->bits_left != 8)
+ bs_write(s, s->bits_left, 0x00);
+}
+
+/* H.264 headers generation functions */
+
+static int tw5864_h264_gen_sps_rbsp(u8 *buf, size_t size, int width, int height)
+{
+ struct bs bs, *s;
+
+ s = &bs;
+ bs_init(s, buf, size);
+ bs_write(s, 8, 0x42); /* profile_idc, baseline */
+ bs_write(s, 1, 1); /* constraint_set0_flag */
+ bs_write(s, 1, 1); /* constraint_set1_flag */
+ bs_write(s, 1, 0); /* constraint_set2_flag */
+ bs_write(s, 5, 0); /* reserved_zero_5bits */
+ bs_write(s, 8, 0x1e); /* level_idc */
+ bs_write_ue(s, 0); /* seq_parameter_set_id */
+ bs_write_ue(s, ilog2(MAX_GOP_SIZE) - 4); /* log2_max_frame_num_minus4 */
+ bs_write_ue(s, 0); /* pic_order_cnt_type */
+ /* log2_max_pic_order_cnt_lsb_minus4 */
+ bs_write_ue(s, ilog2(MAX_GOP_SIZE) - 4);
+ bs_write_ue(s, 1); /* num_ref_frames */
+ bs_write(s, 1, 0); /* gaps_in_frame_num_value_allowed_flag */
+ bs_write_ue(s, width / 16 - 1); /* pic_width_in_mbs_minus1 */
+ bs_write_ue(s, height / 16 - 1); /* pic_height_in_map_units_minus1 */
+ bs_write(s, 1, 1); /* frame_mbs_only_flag */
+ bs_write(s, 1, 0); /* direct_8x8_inference_flag */
+ bs_write(s, 1, 0); /* frame_cropping_flag */
+ bs_write(s, 1, 0); /* vui_parameters_present_flag */
+ bs_rbsp_trailing(s);
+ return bs_len(s);
+}
+
+static int tw5864_h264_gen_pps_rbsp(u8 *buf, size_t size, int qp)
+{
+ struct bs bs, *s;
+
+ s = &bs;
+ bs_init(s, buf, size);
+ bs_write_ue(s, 0); /* pic_parameter_set_id */
+ bs_write_ue(s, 0); /* seq_parameter_set_id */
+ bs_write(s, 1, 0); /* entropy_coding_mode_flag */
+ bs_write(s, 1, 0); /* pic_order_present_flag */
+ bs_write_ue(s, 0); /* num_slice_groups_minus1 */
+ bs_write_ue(s, 0); /* i_num_ref_idx_l0_active_minus1 */
+ bs_write_ue(s, 0); /* i_num_ref_idx_l1_active_minus1 */
+ bs_write(s, 1, 0); /* weighted_pred_flag */
+ bs_write(s, 2, 0); /* weighted_bipred_idc */
+ bs_write_se(s, qp - 26); /* pic_init_qp_minus26 */
+ bs_write_se(s, qp - 26); /* pic_init_qs_minus26 */
+ bs_write_se(s, 0); /* chroma_qp_index_offset */
+ bs_write(s, 1, 0); /* deblocking_filter_control_present_flag */
+ bs_write(s, 1, 0); /* constrained_intra_pred_flag */
+ bs_write(s, 1, 0); /* redundant_pic_cnt_present_flag */
+ bs_rbsp_trailing(s);
+ return bs_len(s);
+}
+
+static int tw5864_h264_gen_slice_head(u8 *buf, size_t size,
+ unsigned int idr_pic_id,
+ unsigned int frame_gop_seqno,
+ int *tail_nb_bits, u8 *tail)
+{
+ struct bs bs, *s;
+ int is_i_frame = frame_gop_seqno == 0;
+
+ s = &bs;
+ bs_init(s, buf, size);
+ bs_write_ue(s, 0); /* first_mb_in_slice */
+ bs_write_ue(s, is_i_frame ? 2 : 5); /* slice_type - I or P */
+ bs_write_ue(s, 0); /* pic_parameter_set_id */
+ bs_write(s, ilog2(MAX_GOP_SIZE), frame_gop_seqno); /* frame_num */
+ if (is_i_frame)
+ bs_write_ue(s, idr_pic_id);
+
+ /* pic_order_cnt_lsb */
+ bs_write(s, ilog2(MAX_GOP_SIZE), frame_gop_seqno);
+
+ if (is_i_frame) {
+ bs_write1(s, 0); /* no_output_of_prior_pics_flag */
+ bs_write1(s, 0); /* long_term_reference_flag */
+ } else {
+ bs_write1(s, 0); /* num_ref_idx_active_override_flag */
+ bs_write1(s, 0); /* ref_pic_list_reordering_flag_l0 */
+ bs_write1(s, 0); /* adaptive_ref_pic_marking_mode_flag */
+ }
+
+ bs_write_se(s, 0); /* slice_qp_delta */
+
+ if (s->bits_left != 8) {
+ *tail = ((s->ptr[0]) << s->bits_left);
+ *tail_nb_bits = 8 - s->bits_left;
+ } else {
+ *tail = 0;
+ *tail_nb_bits = 0;
+ }
+
+ return bs_len(s);
+}
+
+void tw5864_h264_put_stream_header(u8 **buf, size_t *space_left, int qp,
+ int width, int height)
+{
+ int nal_len;
+
+ /* SPS */
+ memcpy(*buf, marker, sizeof(marker));
+ *buf += 4;
+ *space_left -= 4;
+
+ **buf = 0x67; /* SPS NAL header */
+ *buf += 1;
+ *space_left -= 1;
+
+ nal_len = tw5864_h264_gen_sps_rbsp(*buf, *space_left, width, height);
+ *buf += nal_len;
+ *space_left -= nal_len;
+
+ /* PPS */
+ memcpy(*buf, marker, sizeof(marker));
+ *buf += 4;
+ *space_left -= 4;
+
+ **buf = 0x68; /* PPS NAL header */
+ *buf += 1;
+ *space_left -= 1;
+
+ nal_len = tw5864_h264_gen_pps_rbsp(*buf, *space_left, qp);
+ *buf += nal_len;
+ *space_left -= nal_len;
+}
+
+void tw5864_h264_put_slice_header(u8 **buf, size_t *space_left,
+ unsigned int idr_pic_id,
+ unsigned int frame_gop_seqno,
+ int *tail_nb_bits, u8 *tail)
+{
+ int nal_len;
+
+ memcpy(*buf, marker, sizeof(marker));
+ *buf += 4;
+ *space_left -= 4;
+
+ /* Frame NAL header */
+ **buf = (frame_gop_seqno == 0) ? 0x25 : 0x21;
+ *buf += 1;
+ *space_left -= 1;
+
+ nal_len = tw5864_h264_gen_slice_head(*buf, *space_left, idr_pic_id,
+ frame_gop_seqno, tail_nb_bits,
+ tail);
+ *buf += nal_len;
+ *space_left -= nal_len;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-07 03:53:06 +0000