Opened 10 years ago
Closed 10 years ago
#3151 closed defect (fixed)
H.261 encoding: "-mbd rd" seems to confuse order of MBs in GOBs
Reported by: | Maik Merten | Owned by: | |
---|---|---|---|
Priority: | normal | Component: | avcodec |
Version: | git-master | Keywords: | h261 |
Cc: | Blocked By: | ||
Blocking: | Reproduced by developer: | yes | |
Analyzed by developer: | no |
Description
Summary of the bug:
How to reproduce:
% ffmpeg -i tmp/test.y4m -f h261 -vb 256k -mbd rd /tmp/test.h261 ffmpeg version N-58246-g7d0e927 Copyright (c) 2000-2013 the FFmpeg developers built on Nov 18 2013 17:15:01 with gcc 4.8 (Ubuntu/Linaro 4.8.1-10ubuntu8)
Specifying the "-mbd rd" option for H.261 encoding results in massively corrupted output (see attached picture). From the looks of it, it appears that the position of macroblocks within a GOB gets messed up.
Intra frames are unaffected.
Bitrate does not get inflated, quite surprisingly. Internal reference stays intact, but failure to create a correct bitstream?
Attachments (1)
Change History (4)
by , 10 years ago
comment:1 by , 10 years ago
comment:2 by , 10 years ago
Keywords: | h261 added |
---|---|
Reproduced by developer: | set |
Status: | new → open |
Version: | unspecified → git-master |
The output file shows heavy artefacts.
$ ffmpeg -f lavfi -i testsrc=s=352x288 -vb 256k -mbd rd -t 60 out.h261 ffmpeg version N-58249-g2974050 Copyright (c) 2000-2013 the FFmpeg developers built on Nov 18 2013 18:18:50 with gcc 4.7 (SUSE Linux) configuration: --enable-gpl libavutil 52. 53.100 / 52. 53.100 libavcodec 55. 43.101 / 55. 43.101 libavformat 55. 21.100 / 55. 21.100 libavdevice 55. 5.100 / 55. 5.100 libavfilter 3. 91.100 / 3. 91.100 libswscale 2. 5.101 / 2. 5.101 libswresample 0. 17.104 / 0. 17.104 libpostproc 52. 3.100 / 52. 3.100 Input #0, lavfi, from 'testsrc=s=352x288': Duration: N/A, start: 0.000000, bitrate: N/A Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 352x288 [SAR 1:1 DAR 11:9], 25 tbr, 25 tbn, 25 tbc Output #0, h261, to 'out.h261': Metadata: encoder : Lavf55.21.100 Stream #0:0: Video: h261, yuv420p, 352x288 [SAR 1:1 DAR 11:9], q=2-31, 256 kb/s, 90k tbn, 25 tbc Stream mapping: Stream #0:0 -> #0:0 (rawvideo -> h261) Press [q] to stop, [?] for help frame= 1500 fps=877 q=9.3 Lsize= 2217kB time=00:01:00.00 bitrate= 302.7kbits/s video:2217kB audio:0kB subtitle:0 global headers:0kB muxing overhead 0.000000%
comment:3 by , 10 years ago
Resolution: | → fixed |
---|---|
Status: | open → closed |
Fixed in ec312c1fd0d8651f6ef34a101a56c0332e65702e and th previous commit
Note:
See TracTickets
for help on using tickets.
Forgot to mention: Test sequence used is http://media.xiph.org/video/derf/y4m/sign_irene_cif.y4m