From d70dde2712bbead523004d8294ff1a0fdeab480b Mon Sep 17 00:00:00 2001 From: Derek Buitenhuis Date: Wed, 23 Jun 2021 17:12:43 +0100 Subject: [PATCH] avcodec/h264_metadata_bsf: Allow zeroing constraint_set4_flag and constraint_set5_flag These bits are reserved in earlier versions of the H.264 spec, and some poor hardware decoders require they are zero. Thus, it is useful to be able to zero these on streams that may have them set. The result is still a valid H.264 bitstream. Signed-off-by: Derek Buitenhuis --- doc/bitstream_filters.texi | 5 +++++ libavcodec/h264_metadata_bsf.c | 8 ++++++++ libavcodec/version.h | 2 +- 3 files changed, 14 insertions(+), 1 deletion(-) diff --git a/doc/bitstream_filters.texi b/doc/bitstream_filters.texi index 60e729484d..e3c56f1887 100644 --- a/doc/bitstream_filters.texi +++ b/doc/bitstream_filters.texi @@ -253,6 +253,11 @@ Set whether the stream has fixed framerate - typically this indicates that the framerate is exactly half the tick rate, but the exact meaning is dependent on interlacing and the picture structure (see H.264 section E.2.1 and table E-6). +@item zero_new_constraint_set_flags +Zero constraint_set4_flag and constraint_set5_flag in the SPS. These +bits were reserved in a previous version of the H.264 spec, and thus +some hardware decoders require these to be zero. The result of zeroing +this is still a valid bitstream. @item crop_left @item crop_right diff --git a/libavcodec/h264_metadata_bsf.c b/libavcodec/h264_metadata_bsf.c index ef74cba560..452a8ec5dc 100644 --- a/libavcodec/h264_metadata_bsf.c +++ b/libavcodec/h264_metadata_bsf.c @@ -61,6 +61,7 @@ typedef struct H264MetadataContext { AVRational tick_rate; int fixed_frame_rate_flag; + int zero_new_constraint_set_flags; int crop_left; int crop_right; @@ -228,6 +229,10 @@ static int h264_metadata_update_sps(AVBSFContext *bsf, need_vui = 1; } SET_VUI_FIELD(fixed_frame_rate_flag); + if (ctx->zero_new_constraint_set_flags) { + sps->constraint_set4_flag = 0; + sps->constraint_set5_flag = 0; + } if (sps->separate_colour_plane_flag || sps->chroma_format_idc == 0) { crop_unit_x = 1; @@ -618,6 +623,9 @@ static const AVOption h264_metadata_options[] = { { "fixed_frame_rate_flag", "Set VUI fixed frame rate flag", OFFSET(fixed_frame_rate_flag), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 1, FLAGS }, + { "zero_new_constraint_set_flags", "Set constraint_set4_flag / constraint_set5_flag to zero", + OFFSET(zero_new_constraint_set_flags), AV_OPT_TYPE_BOOL, + { .i64 = 0 }, 0, 1, FLAGS }, { "crop_left", "Set left border crop offset", OFFSET(crop_left), AV_OPT_TYPE_INT, diff --git a/libavcodec/version.h b/libavcodec/version.h index 1288cecebe..2a420a7e28 100644 --- a/libavcodec/version.h +++ b/libavcodec/version.h @@ -28,7 +28,7 @@ #include "libavutil/version.h" #define LIBAVCODEC_VERSION_MAJOR 59 -#define LIBAVCODEC_VERSION_MINOR 2 +#define LIBAVCODEC_VERSION_MINOR 3 #define LIBAVCODEC_VERSION_MICRO 100 #define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \