[FFmpeg-devel] The log level of "co located POCs unavailable" should not be ERROR

Yukun Guo gyk.net at gmail.com
Thu Feb 28 05:33:50 EET 2019


The error message "co located POCs unavailable" is reported when the
co-located picture of an H.264 B frame is missing during spatial direct
predition. It comes from this line:
https://github.com/FFmpeg/FFmpeg/blob/n4.1.1/libavcodec/h264_direct.c#L156
and was originally commited for solving an issue found by fuzzing:
https://bugzilla.mozilla.org/show_bug.cgi?id=1230286.

I think the condition is quite normal for live streaming, 1) when the
player first connects to the streaming server, it may receive B frames
whose reference frames have never been sent; 2) when the bandwidth is
limited, the server purposely drops packets due to buffer overflow.
IMHO the log level should be on par with "Frame num gap" (if
`gaps_in_frame_num_value_allowed_flag` is false) and "no picture"
(both are found in h264_slice.c and use DEBUG level).


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