[FFmpeg-trac] #9764(avcodec:new): MP3 decoding errors on ARMv4 hardware

[FFmpeg]

#9764: MP3 decoding errors on ARMv4 hardware
-------------------------------------+-------------------------------------
             Reporter:  David        |                    Owner:  (none)
  Fletcher                           |
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:  avcodec
              Version:  git-master   |               Resolution:
             Keywords:  mp3 arm      |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Comment (by David Fletcher):

 Example of the console output running on the ARMv4 machine (in this case
 using the transcode_v4_ffmpeg.c file already attached compiled against the
 latest source, snapshot N-107787-gc469c3c3b1). The transcode_v4_ffmpeg.c
 file was updated to read the source file (s-32-44100.mp3) which is
 attached to this ticket rather than the internet radio stream originally
 read. This is selected as characteristic of a low bitrate internet stream
 which is where the problem on arm4 hardware comes to light.


 {{{
 ./transcode_arm4
 [NULL @ 0x191d30] Opening
 'http://www.megapico.co.uk/sharpfin/s-32-44100.mp3' for reading
 [http @ 0x192060] Setting default whitelist
 'http,https,tls,rtp,tcp,udp,crypto,httpproxy,data'
 [tcp @ 0x194b20] Original list of addresses:
 [tcp @ 0x194b20] Address 80.229.167.224 port 80
 [tcp @ 0x194b20] Interleaved list of addresses:
 [tcp @ 0x194b20] Address 80.229.167.224 port 80
 [tcp @ 0x194b20] Starting connection attempt to 80.229.167.224 port 80
 [tcp @ 0x194b20] Successfully connected to 80.229.167.224 port 80
 [http @ 0x192060] request: GET /sharpfin/s-32-44100.mp3 HTTP/1.1
 User-Agent: Lavf/59.30.100
 Accept: */*
 Range: bytes=0-
 Connection: close
 Host: www.megapico.co.uk
 Icy-MetaData: 1


 [mp3 @ 0x191d30] Format mp3 probed with size=131072 and score=51
 id3v2 ver:3 flags:00 len:65526
 [mp3 @ 0x191d30] Skipping 0 bytes of junk at 65536.
 [mp3 @ 0x191d30] Before avformat_find_stream_info() pos: 65536 bytes
 read:131445 seeks:0 nb_streams:1
 [mp3 @ 0x191d30] All info found
 [mp3 @ 0x191d30] Estimating duration from bitrate, this may be inaccurate
 [mp3 @ 0x191d30] After avformat_find_stream_info() pos: 71680 bytes
 read:131445 seeks:0 frames:50
 Input #0, mp3, from 'http://www.megapico.co.uk/sharpfin/s-32-44100.mp3':
   Metadata:
     title           : 190130
     album           : Podnews
     artist          : James Cridland
     album_artist    : James Cridland
     comment         : Visit https://podnews.net to get our daily
 newsletter, free
     track           : 190130
     RAD             :
 {"remoteAudioData":{"episodeID":"generic","trackingUrls":["https://podnews.net/rad"],"events":[{"eventTime":"00:00:00.000","label":"RAD0"},
 {"eventTime":"00:00:56.570","label":"RAD50"}],"podcastID":"podnews"}}
     genre           : Podcast
     copyright       : Amazingly Brilliant Pty Ltd
     encoded_by      : Hindenburg Journalist Pro 1.82.2312
     date            : 2019
   Duration: 00:00:56.72, start: 0.000000, bitrate: 41 kb/s
   Stream #0:0, 50, 1/14112000: Audio: mp3, 44100 Hz, stereo, s16p, 32 kb/s
 Frame rate 1: 44100
 Too much data!!
 [file @ 0x198540] Setting default whitelist 'file,crypto,data'
 [SWR @ 0x1ae790] Using s16p internally between filters
 Incoming bit rate: 32000Frame rate: 44100
 [AVIOContext @ 0x198590] Statistics: 9215276 bytes written, 2 seeks, 37
 writeouts
 [AVIOContext @ 0x19d820] Statistics: 292407 bytes read, 0 seeks
 }}}

 The output on ARMv4 is distorted relative to the original. The same code
 running on X86-64 (intel i5) produces output that is not distorted.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/9764#comment:3>
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