h264_metadata BSF lacks overscan

[Anton Torp]

Summary of the bug:

The "libx264" encoder has the parameter to set the overscan flag using "--overscan <string>".

However, when using any of the H.264 HW encoders, all of them forget the option to set the overscan flag.

Futhermore, the "h264_metadata" filter can be used to set (or unset) some Video Usability Info parameters of the H.264 bitstream. For example:

• video_format
• video_full_range_flag
• colour_primaries
• transfer_characteristics
• matrix_coefficients
• chroma_sample_loc_type

But it lacks the "--overscan" flag.
So I request to include support for this flag in the h264_metadata BSF.

Thank you!

[Anton Torp]

Hi,

Inside the H264RawVUI struct it's defined:

uint8_t overscan_info_present_flag;
uint8_t overscan_appropriate_flag;

So, to add support for the "--overscan" parameter it's sufficient to mod the function "h264_metadata_update_sps()" in the "libavcodec/h264_metadata_bsf.c" source.

I hope some developer will add support for it. As it's the only solution to use HARDWARE encoding and set this flag.

Thank you!

[Anton Torp]

Hi,

I see that one developer (Thank you Mark!) has implemented it:
​https://patchwork.ffmpeg.org/patch/14108/

[jkqxz]

Implemented in b123d0780ec26456b08cd50e1062d464262ceb38.