[FFmpeg-trac] #2122(swresample:new): Commit 75d900d makes skipping in the input while using swresample very slow

[FFmpeg]

#2122: Commit 75d900d makes skipping in the input while using swresample very slow
------------------------------------+--------------------------------------
             Reporter:  eelco       |                    Owner:  michael
                 Type:  defect      |                   Status:  new
             Priority:  important   |                Component:  swresample
              Version:  git-master  |               Resolution:
             Keywords:  regression  |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
------------------------------------+--------------------------------------

Comment (by eelco):

 I found out it only seems reproducible with a 5.1 audio track. The test
 below is with the 720p version of Sintel, downloaded from
 http://www.sintel.org/download

 {{{
 time ./ffmpeg -ss 2 -i ~/Downloads/Sintel.2010.720p.mkv  -t 1 -vcodec copy
 -f matroska -map 0:0 -acodec ac3 -async 1 -map 0:1 -y /dev/null
 ffmpeg version N-48635-g8615970 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Jan  8 2013 15:38:39 with llvm-gcc 4.2.1 (LLVM build
 2336.11.00)
   configuration: --prefix=/Users/eelco/Projects/Beamer/FFmpeg/build
 --enable-gpl --enable-version3 --enable-libx264 --disable-shared --enable-
 static --enable-libtheora --enable-libvorbis --enable-libvo-aacenc
 --disable-doc --extra-cflags='-DMACOSX_DEPLOYMENT_TARGET=10.6 -isysroot
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk
 -mmacosx-version-min=10.6
 -I/Users/eelco/Projects/Beamer/FFmpeg/build/include' --extra-
 ldflags='-isysroot
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk
 -mmacosx-version-min=10.6 -L/Users/eelco/Projects/Beamer/FFmpeg/build/lib'
   libavutil      52. 13.100 / 52. 13.100
   libavcodec     54. 86.100 / 54. 86.100
   libavformat    54. 59.106 / 54. 59.106
   libavdevice    54.  3.102 / 54.  3.102
   libavfilter     3. 32.100 /  3. 32.100
   libswscale      2.  1.103 /  2.  1.103
   libswresample   0. 17.102 /  0. 17.102
   libpostproc    52.  2.100 / 52.  2.100
 Input #0, matroska,webm, from
 '/Users/eelco/Downloads/Sintel.2010.720p.mkv':
   Metadata:
     creation_time   : 2011-04-24 17:20:33
   Duration: 00:14:48.03, start: 0.000000, bitrate: 6071 kb/s
     Chapter #0.0: start 0.000000, end 103.125000
     Metadata:
       title           : Chapter 01
     Chapter #0.1: start 103.125000, end 148.667000
     Metadata:
       title           : Chapter 02
     Chapter #0.2: start 148.667000, end 349.792000
     Metadata:
       title           : Chapter 03
     Chapter #0.3: start 349.792000, end 437.208000
     Metadata:
       title           : Chapter 04
     Chapter #0.4: start 437.208000, end 472.075000
     Metadata:
       title           : Chapter 05
     Chapter #0.5: start 472.075000, end 678.833000
     Metadata:
       title           : Chapter 06
     Chapter #0.6: start 678.833000, end 744.083000
     Metadata:
       title           : Chapter 07
     Chapter #0.7: start 744.083000, end 888.032000
     Metadata:
       title           : Chapter 08
     Stream #0:0(eng): Video: h264 (High), yuv420p, 1280x544, SAR 1:1 DAR
 40:17, 24 fps, 24 tbr, 1k tbn, 48 tbc
     Stream #0:1(eng): Audio: ac3, 48000 Hz, 5.1(side), fltp, 640 kb/s
     Metadata:
       title           : AC3 5.1 @ 640 Kbps
     Stream #0:2(ger): Subtitle: subrip
     Stream #0:3(eng): Subtitle: subrip
     Stream #0:4(spa): Subtitle: subrip
     Stream #0:5(fre): Subtitle: subrip
     Stream #0:6(ita): Subtitle: subrip
     Stream #0:7(dut): Subtitle: subrip
     Stream #0:8(pol): Subtitle: subrip
     Stream #0:9(por): Subtitle: subrip
     Stream #0:10(rus): Subtitle: subrip
     Stream #0:11(vie): Subtitle: subrip
 -async is forwarded to lavfi similarly to -af
 aresample=async=1:min_hard_comp=0.100000.
 Output #0, matroska, to '/dev/null':
   Metadata:
     encoder         : Lavf54.59.106
     Chapter #0.0: start 0.000000, end 1.000000
     Metadata:
       title           : Chapter 01
     Stream #0:0(eng): Video: h264, yuv420p, 1280x544 [SAR 1:1 DAR 40:17],
 q=2-31, 24 fps, 1k tbn, 1k tbc
     Stream #0:1(eng): Audio: ac3, 48000 Hz, 5.1(side), fltp, 448 kb/s
     Metadata:
       title           : AC3 5.1 @ 640 Kbps
 Stream mapping:
   Stream #0:0 -> #0:0 (copy)
   Stream #0:1 -> #0:1 (ac3 -> ac3)
 Press [q] to stop, [?] for help
 frame=   74 fps=7.1 q=-1.0 Lsize=     305kB time=00:00:01.01
 bitrate=2454.6kbits/s
 video:248kB audio:56kB subtitle:0 global headers:0kB muxing overhead
 0.512768%
        10.44 real         3.72 user         6.71 sys
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2122#comment:5>
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