lavc: Add h264_metadata bitstream filter

This is able to modify some header metadata found in the SPS/VUI,
and can also add/remove AUDs and insert user data in SEI NAL units.

configure

@@ -2323,6 +2323,7 @@ vc1_parser_select="vc1dsp"
 
 # bitstream_filters
 aac_adtstoasc_bsf_select="adts_header"
+h264_metadata_bsf_select="cbs_h264"
 mjpeg2jpeg_bsf_select="jpegtables"
 trace_headers_bsf_select="cbs_h264 cbs_h265"
 

doc/bitstream_filters.texi

@@ -39,6 +39,69 @@ When this option is enabled, the long-term headers are removed from the
 bitstream after extraction.
 @end table
 
+@section h264_metadata
+
+Modify metadata embedded in an H.264 stream.
+
+@table @option
+@item aud
+Insert or remove AUD NAL units in all access units of the stream.
+
+@table @samp
+@item insert
+@item remove
+@end table
+
+@item sample_aspect_ratio
+Set the sample aspect ratio of the stream in the VUI parameters.
+
+@item video_format
+@item video_full_range_flag
+Set the video format in the stream (see H.264 section E.2.1 and
+table E-2).
+
+@item colour_primaries
+@item transfer_characteristics
+@item matrix_coefficients
+Set the colour description in the stream (see H.264 section E.2.1
+and tables E-3, E-4 and E-5).
+
+@item chroma_sample_loc_type
+Set the chroma sample location in the stream (see H.264 section
+E.2.1 and figure E-1).
+
+@item tick_rate
+Set the tick rate (num_units_in_tick / time_scale) in the VUI
+parameters.  This is the smallest time unit representable in the
+stream, and in many cases represents the field rate of the stream
+(double the frame rate).
+@item fixed_frame_rate_flag
+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 crop_left
+@item crop_right
+@item crop_top
+@item crop_bottom
+Set the frame cropping offsets in the SPS.  These values will replace
+the current ones if the stream is already cropped.
+
+These fields are set in pixels.  Note that some sizes may not be
+representable if the chroma is subsampled or the stream is interlaced
+(see H.264 section 7.4.2.1.1).
+
+@item sei_user_data
+Insert a string as SEI unregistered user data.  The argument must
+be of the form @emph{UUID+string}, where the UUID is as hex digits
+possibly separated by hyphens, and the string can be anything.
+
+For example, @samp{086f3693-b7b3-4f2c-9653-21492feee5b8+hello} will
+insert the string ``hello'' associated with the given UUID.
+
+@end table
+
 @section h264_mp4toannexb
 
 @section imx_dump_header

libavcodec/Makefile

@@ -776,6 +776,7 @@ OBJS-$(CONFIG_CHOMP_BSF)                  += chomp_bsf.o
 OBJS-$(CONFIG_DUMP_EXTRADATA_BSF)         += dump_extradata_bsf.o
 OBJS-$(CONFIG_EXTRACT_EXTRADATA_BSF)      += extract_extradata_bsf.o    \
                                              h2645_parse.o
+OBJS-$(CONFIG_H264_METADATA_BSF)          += h264_metadata_bsf.o
 OBJS-$(CONFIG_H264_MP4TOANNEXB_BSF)       += h264_mp4toannexb_bsf.o
 OBJS-$(CONFIG_HEVC_MP4TOANNEXB_BSF)       += hevc_mp4toannexb_bsf.o
 OBJS-$(CONFIG_IMX_DUMP_HEADER_BSF)        += imx_dump_header_bsf.o

libavcodec/bitstream_filters.c

@@ -28,6 +28,7 @@ extern const AVBitStreamFilter ff_aac_adtstoasc_bsf;
 extern const AVBitStreamFilter ff_chomp_bsf;
 extern const AVBitStreamFilter ff_dump_extradata_bsf;
 extern const AVBitStreamFilter ff_extract_extradata_bsf;
+extern const AVBitStreamFilter ff_h264_metadata_bsf;
 extern const AVBitStreamFilter ff_h264_mp4toannexb_bsf;
 extern const AVBitStreamFilter ff_hevc_mp4toannexb_bsf;
 extern const AVBitStreamFilter ff_imx_dump_header_bsf;