[FFmpeg-devel] [PATCH 1/1] avformat/mpegenc.c: vbvsize option

[Gaullier Nicolas]

>>On Thu, Oct 31, 2019 at 06:04:58PM +0100, Nicolas Gaullier wrote:
>> Allow the user to set or override the vbv size
>> ---
>>  libavformat/mpegenc.c | 6 +++++-
>>  1 file changed, 5 insertions(+), 1 deletion(-)
>
>This is not the "correct" way to handle this, because one mpeg container
>can contain many streams and this is just one parameter for the container.
>while the vbvsize is a parameter per stream.

FYI, my main concern/use case is to be able to rewrap an input mpg file to a new mpg file while keeping its vbv size.
This was working back in version 2.8.9, just before codecpar was introduced (ie. regression)...
My first proposal would be very straightforward : insert a new "rc_buffer_size" field at the end of AVCodecParameters but that would break the ABI?
Another point is that rc_buffer_size may be carried by stream side_data when encoding, so that would mean two representations for the same information, I don't know if this sounds "correct".
At the end, do you think amending AVCodecParameters would be acceptable ?
The fact is, I have no other idea because I don't see anyway how to setup stream side_data from within the codec of the input stream.
Thank you for your review and ... help
Nicolas