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h264parse: decode SPS

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Lin YANG 2009-08-17 17:51:10 +08:00 committed by Sebastian Dröge
parent 90dfda0f46
commit 2531e5f584
1 changed files with 96 additions and 0 deletions
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96
gst/h264parse/gsth264parse.c
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@ -455,6 +455,102 @@ gst_sps_decode_vui (GstH264Parse * h, GstNalBs * bs)
} }
} }
/* decode sequential parameter sets */
static gboolean
gst_nal_decode_sps (GstH264Parse * h, GstNalBs * bs)
{
guint8 profile_idc, level_idc;
guint8 sps_id;
GstH264Sps *sps = NULL;
profile_idc = gst_nal_bs_read (bs, 8);
gst_nal_bs_read (bs, 1); /* constraint_set0_flag */
gst_nal_bs_read (bs, 1); /* constraint_set1_flag */
gst_nal_bs_read (bs, 1); /* constraint_set2_flag */
gst_nal_bs_read (bs, 1); /* constraint_set3_flag */
gst_nal_bs_read (bs, 4); /* reserved */
level_idc = gst_nal_bs_read (bs, 8);
sps_id = gst_nal_bs_read_ue (bs);
sps = gst_h264_parse_get_sps (h, sps_id);
if (sps == NULL) {
return FALSE;
}
sps->profile_idc = profile_idc;
sps->level_idc = level_idc;
if (profile_idc == 100 || profile_idc == 110 || profile_idc == 122
|| profile_idc == 244 || profile_idc == 44 ||
profile_idc == 83 || profile_idc == 86) {
if (gst_nal_bs_read_ue (bs) == 3) { /* chroma_format_idc */
gst_nal_bs_read (bs, 1); /* separate_colour_plane_flag */
}
gst_nal_bs_read_ue (bs); /* bit_depth_luma_minus8 */
gst_nal_bs_read_ue (bs); /* bit_depth_chroma_minus8 */
gst_nal_bs_read (bs, 1); /* qpprime_y_zero_transform_bypass_flag */
if (gst_nal_bs_read (bs, 1)) { /* seq_scaling_matrix_present_flag */
/* TODO: unfinished */
}
}
sps->log2_max_frame_num_minus4 = gst_nal_bs_read_ue (bs); /* between 0 and 12 */
if (sps->log2_max_frame_num_minus4 > 12) {
GST_DEBUG_OBJECT (h, "log2_max_frame_num_minus4 = %d out of range"
" [0,12]", sps->log2_max_frame_num_minus4);
return FALSE;
}
sps->pic_order_cnt_type = gst_nal_bs_read_ue (bs);
if (sps->pic_order_cnt_type == 0) {
sps->log2_max_pic_order_cnt_lsb_minus4 = gst_nal_bs_read_ue (bs);
} else if (sps->pic_order_cnt_type == 1) {
/* TODO: unfinished */
/*
delta_pic_order_always_zero_flag = gst_nal_bs_read (bs, 1);
offset_for_non_ref_pic = gst_nal_bs_read_se (bs);
offset_for_top_to_bottom_field = gst_nal_bs_read_se (bs);
num_ref_frames_in_pic_order_cnt_cycle = gst_nal_bs_read_ue (bs);
for( i = 0; i < num_ref_frames_in_pic_order_cnt_cycle; i++ )
offset_for_ref_frame[i] = gst_nal_bs_read_se (bs);
*/
}
gst_nal_bs_read_ue (bs); /* max_num_ref_frames */
gst_nal_bs_read (bs, 1); /* gaps_in_frame_num_value_allowed_flag */
gst_nal_bs_read_ue (bs); /* pic_width_in_mbs_minus1 */
gst_nal_bs_read_ue (bs); /* pic_height_in_map_units_minus1 */
sps->frame_mbs_only_flag = gst_nal_bs_read (bs, 1);
if (!sps->frame_mbs_only_flag) {
gst_nal_bs_read (bs, 1); /* mb_adaptive_frame_field_flag */
}
gst_nal_bs_read (bs, 1); /* direct_8x8_inference_flag */
if (gst_nal_bs_read (bs, 1)) { /* frame_cropping_flag */
gst_nal_bs_read_ue (bs); /* frame_crop_left_offset */
gst_nal_bs_read_ue (bs); /* frame_crop_right_offset */
gst_nal_bs_read_ue (bs); /* frame_crop_top_offset */
gst_nal_bs_read_ue (bs); /* frame_crop_bottom_offset */
}
GST_DEBUG_OBJECT (h, "Decoding SPS: profile_idc = %d, "
"level_idc = %d, "
"sps_id = %d, "
"pic_order_cnt_type = %d, "
"frame_mbs_only_flag = %d\n",
sps->profile_idc,
sps->level_idc,
sps_id, sps->pic_order_cnt_type, sps->frame_mbs_only_flag);
sps->vui_parameters_present_flag = gst_nal_bs_read (bs, 1);
if (sps->vui_parameters_present_flag) {
gst_sps_decode_vui (h, bs);
}
return TRUE;
}
GST_BOILERPLATE (GstH264Parse, gst_h264_parse, GstElement, GST_TYPE_ELEMENT); GST_BOILERPLATE (GstH264Parse, gst_h264_parse, GstElement, GST_TYPE_ELEMENT);