[FFmpeg-trac] #3233(undetermined:new): PSP PMF audio

FFmpeg trac at avcodec.org
Sun Sep 25 01:29:06 EEST 2016


#3233: PSP PMF audio
-------------------------------------+-------------------------------------
             Reporter:  cehoyos      |                    Owner:
                 Type:  enhancement  |                   Status:  new
             Priority:  wish         |                Component:
              Version:  git-master   |  undetermined
             Keywords:  mpegps pmf   |               Resolution:
  atrac3 atrac3p videolan            |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Comment (by bazz):

 == Solution Found for PMF Freezing ==
 I have discovered why the ATRAC3+ parsing failed on my PMF sample and have
 made a solution.

 The problem was that the ATRAC3+ parser did not properly process a buffer
 that only contains one full header.

 I am attaching both a complete patch (parser.diff), and a patch that shows
 only my changes from
 https://ffmpeg.org/pipermail/ffmpeg-devel/2014-December/166169.html
 (parser_partial.diff)

 == ffmpeg Mod to Transcode PMF ==

 Using the latest FFmpeg from Github
 (7d17d31db4322b0c5e89f889ebf32af9ca2d91a9),
 ffplay works out of the box with the PMF patch. But, I found that I have
 to modify one more thing for the ffmpeg tool to work. Let me detail the
 issue, then provide the solution.

 Here is a log of an attempt to transcode a PMF to avi.
 {{{
 bazz at awesomesauce ~/Code/FFmpeg $ ./ffmpeg -i ~/3rd/008.pmf -vcodec copy
 /tmp/derp.avi
 ffmpeg version git-2016-09-23-ae2cd8a Copyright (c) 2000-2016 the FFmpeg
 developers
   built with gcc 4.9.3 (Gentoo 4.9.3 p1.5, pie-0.6.4)
   configuration:
   libavutil      55. 30.100 / 55. 30.100
   libavcodec     57. 57.101 / 57. 57.101
   libavformat    57. 50.100 / 57. 50.100
   libavdevice    57.  0.102 / 57.  0.102
   libavfilter     6. 62.100 /  6. 62.100
   libswscale      4.  1.100 /  4.  1.100
   libswresample   2.  1.100 /  2.  1.100
 [atrac3plus @ 0x3fbedc0] block_align is not set
 Input #0, mpeg, from '/home/bazz/3rd/008.pmf':
   Duration: 00:00:50.48, start: 0.945211, bitrate: 1320 kb/s
     Stream #0:0[0x1e0]: Video: h264 (Main), yuv420p(tv, smpte170m),
 480x272 [SAR 1:1 DAR 30:17], 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
     Stream #0:1[0x1bd0]: Audio: atrac3p, 44100 Hz, stereo, 128 kb/s
 [abuffer @ 0x404db40] Unable to parse option value "(null)" as sample
 format
     Last message repeated 1 times
 [abuffer @ 0x404db40] Error setting option sample_fmt to value (null).
 [graph 0 input from stream 0:1 @ 0x404da40] Error applying options to the
 filter
 }}}

 The issue stems from the fact that `block_align is not set`, because in
 `libavcodec/atrac3plusdec.c:147` `atrac3p_decode_init()` will fail in this
 case. I can say that commenting out the `block_align` return statement
 allows `ffmpeg` to once again apparently run flawlessly with PMF. Let it
 be known here that the PMF parser constantly updates the `block_align`
 anyways.

 Thus, I'm not sure if removing the logic check produces issues for other
 users of ATRAC3+, but it at least provides with me a usable latest version
 of FFmpeg for the purpose of working with these PMF videos.

 Anyhow, I'm attaching this patch as "ffmpeg.diff"

 Note: Using a ~Dec 2014 commit of FFmpeg did not require this
 modification, but
 I did not discover why.

 == Closing Remarks ==

 Check out the new attachment I added to this ticket `bazz_patches.zip`
 Remember, I'm using the latest FFmpeg from Github
 (7d17d31db4322b0c5e89f889ebf32af9ca2d91a9)

--
Ticket URL: <https://trac.ffmpeg.org/ticket/3233#comment:5>
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