Opened 5 years ago
Last modified 5 years ago
#8343 open enhancement
h261dec doesn't mark keyframes
| Reported by: | Lastique | Owned by: | |
|---|---|---|---|
| Priority: | wish | Component: | avcodec |
| Version: | git-master | Keywords: | h261 |
| Cc: | Blocked By: | ||
| Blocking: | Reproduced by developer: | no | |
| Analyzed by developer: | no |
Description
h261dec does not set AVFrame::key_frame field on keyframes. As a side effect, frame skipping except keyframes doesn't work (all frames are skipped).
In H.261, keyframes are normally indicated by the Freeze Picture Release bit in the Picture Header of a frame, but h261dec ignores that bit. h261enc behavior is to set that bit on keyframes.
The problem was discovered in a client application that uses ffmpeg through its C API. I'm not sure if it can be reproduced through command line.
Attached is a patch that fixes the problem. The patch has been posted on ffmpeg-devel:
https://lists.ffmpeg.org/pipermail/ffmpeg-devel/2019-October/252145.html
Attachments (1)
Change History (6)
by , 5 years ago
| Attachment: | 11_fix_h261dec_keyframe.patch added |
|---|
follow-up: 4 comment:1 by , 5 years ago
| Blocked By: | → h261 |
|---|---|
| Priority: | normal → wish |
| Type: | defect → enhancement |
| Version: | 4.2 → git-master |
The patch is ignored here and will not be backported.
comment:2 by , 5 years ago
| Blocked By: | h261 |
|---|---|
| Keywords: | h261 added |
comment:3 by , 5 years ago
| Type: | enhancement → defect |
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I disagree with "enhancement" qualification, this is a bug.
comment:4 by , 5 years ago
| Status: | new → open |
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Replying to cehoyos:
The patch is ignored here and will not be backported.
The patch is here https://patchwork.ffmpeg.org/patch/15972/
comment:5 by , 5 years ago
| Type: | defect → enhancement |
|---|
A patch to fix keyframe markup in h261dec