Seeking performance regression

[Carl Eugen Hoyos]

​http://thread.gmane.org/gmane.comp.video.ffmpeg.user/60315
Seeking in a very large aac file with FFplay (and MPlayer) takes longer since 7f5af80ba42bbd82da53dfd95236e9d47159a96a

$ ffmpeg -f lavfi -i "sine=frequency=800:duration=7200" -c:a aac -b:a 320k test.aac

Trying to seek in this file with Page-Up takes significantly longer than before.

$ ffplay test.aac
ffplay version N-77567-g29e6606 Copyright (c) 2003-2015 the FFmpeg developers
  built with gcc 4.7 (SUSE Linux)
  configuration: --enable-gpl
  libavutil      55. 11.100 / 55. 11.100
  libavcodec     57. 20.100 / 57. 20.100
  libavformat    57. 21.100 / 57. 21.100
  libavdevice    57.  0.100 / 57.  0.100
  libavfilter     6. 22.100 /  6. 22.100
  libswscale      4.  0.100 /  4.  0.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
[aac @ 0x7ff9b0000920] Estimating duration from bitrate, this may be inaccurate
Input #0, aac, from 'test.aac':
  Duration: 02:04:19.00, bitrate: 144 kb/s
    Stream #0:0: Audio: aac (LC), 44100 Hz, mono, fltp, 144 kb/s
 761.17 M-A:  0.000 fd=   0 aq=   13KB vq=    0KB sq=    0B f=0/0

In addition, the seek is very imprecise, I quit immediately after the seek that should have been to 600 seconds.
The performance regression is also reproducible with FFmpeg:

$ time ./ffmpeg -ss 1:45:00 -i test.aac -f null -
ffmpeg version N-76321-g856b19d Copyright (c) 2000-2015 the FFmpeg developers
  built with gcc 4.7 (SUSE Linux)
  configuration:
  libavutil      55.  4.100 / 55.  4.100
  libavcodec     57. 11.100 / 57. 11.100
  libavformat    57. 11.100 / 57. 11.100
  libavdevice    57.  0.100 / 57.  0.100
  libavfilter     6. 14.100 /  6. 14.100
  libswscale      4.  0.100 /  4.  0.100
  libswresample   2.  0.100 /  2.  0.100
[aac @ 0x23ec3e0] Estimating duration from bitrate, this may be inaccurate
Input #0, aac, from 'test.aac':
  Duration: 02:04:19.00, bitrate: 144 kb/s
    Stream #0:0: Audio: aac (LC), 44100 Hz, mono, fltp, 150 kb/s
Output #0, null, to 'pipe:':
  Metadata:
    encoder         : Lavf57.11.100
    Stream #0:0: Audio: pcm_s16le, 44100 Hz, mono, s16, 705 kb/s
    Metadata:
      encoder         : Lavc57.11.100 pcm_s16le
Stream mapping:
  Stream #0:0 -> #0:0 (aac (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
size=N/A time=00:15:00.04 bitrate=N/A
video:0kB audio:77523kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

real    0m1.242s
user    0m1.219s
sys     0m0.022s

$ time ./ffmpeg -ss 1:45:00 -i test.aac -f null -
ffmpeg version N-76323-g7f5af80 Copyright (c) 2000-2015 the FFmpeg developers
  built with gcc 4.7 (SUSE Linux)
  configuration:
  libavutil      55.  4.100 / 55.  4.100
  libavcodec     57. 12.100 / 57. 12.100
  libavformat    57. 11.100 / 57. 11.100
  libavdevice    57.  0.100 / 57.  0.100
  libavfilter     6. 14.100 /  6. 14.100
  libswscale      4.  0.100 /  4.  0.100
  libswresample   2.  0.100 /  2.  0.100
[aac @ 0x24993e0] Estimating duration from bitrate, this may be inaccurate
Input #0, aac, from 'test.aac':
  Duration: 02:04:19.00, bitrate: 144 kb/s
    Stream #0:0: Audio: aac (LC), 44100 Hz, mono, fltp, 4 kb/s
Output #0, null, to 'pipe:':
  Metadata:
    encoder         : Lavf57.11.100
    Stream #0:0: Audio: pcm_s16le, 44100 Hz, mono, s16, 705 kb/s
    Metadata:
      encoder         : Lavc57.12.100 pcm_s16le
Stream mapping:
  Stream #0:0 -> #0:0 (aac (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
size=N/A time=00:15:00.04 bitrate=N/A
video:0kB audio:77523kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

real    0m1.361s
user    0m1.339s
sys     0m0.022s

[Hendrik]

Can you give the attached patch a try?

[Andy Furniss]

Seems to fix for me, testing with ffplay.

[Carl Eugen Hoyos]

Fixed by Hendrik in b966a403dd80604bb7dbb9ee6ec331ade0e84953