如何使用FFprobe查看视频切片/帧的参考列表

Question

Suppose I have a avi/mkv/mp4 video, the video has some GOP structure( IPPP/IBBP etc) which can be seen from FFprobe. But can I see reference picture list(L0 and L1), that is frames from which B is using bi-directional prediction using FFprobe?

Answer 1

Since this information is idiosyncratic to each bitstream syntax (codec), it's in the purview of the decoder. So I don't believe ffprobe can access it.

-- Untested approach follows --

Looking at the source code, it seems you have to define TRACE (let's say, in libavutil/log.h ), compile and run

ffmpeg -loglevel trace -i in.mp4 -f null - 2> log.txt

Then the log should contain lines of the format

List0: %s fn:%d 0x%p
List1: %s fn:%d 0x%p

where the %d field will have the picture ID.