[FFmpeg-trac] #1693(avcodec:new): AAC Scalable Sample Rate (SSR)

[FFmpeg]

#1693: AAC Scalable Sample Rate (SSR)
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             Reporter:  cehoyos     |                    Owner:
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  avcodec
              Version:  git-master  |               Resolution:
             Keywords:  aac         |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
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Comment (by dalecurtis):

 Okay, the as08_32.mp4 file is corrupt. It's only 50kb but has sample
 indices into the 90kb+ range, so the ssr drop patch I attached works fine.

 Also, the ssr_chrome.aac file, plus a couple more samples I received, were
 created by libfaac 1.26.1, which has never had support for writing gain
 control data:
 https://sourceforge.net/p/faac/faac/ci/648c55c5a0a049e557ac6d40ffe56ef49d4682a7/tree/libfaac/bitstream.c#l716
 -- so that file is simply corrupt. The encoding string can be found in a
 hexdump of the file:

 00000000  ff f1 4c 80 07 5f fc de  36 00 00 6c 69 62 66 61
 |..L.._..6..libfa|
 00000010  61 63 20 31 2e 32 36 2e  31 20 28 4e 6f 76 20 31  |ac 1.26.1
 (Nov 1|
 00000020  34 20 32 30 31 30 29 20  55 4e 53 54 41 42 4c 45  |4 2010)
 UNSTABLE|

 As such I've attached the same ssr drop patch again with attribution to
 Robert Swain, who seems to be the author of the original patch set per the
 ffmpeg-devel e-mails. I'll send this to ffmpeg-devel and we can continue
 discussion there as to whether this should be submitted.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/1693#comment:33>
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