[FFmpeg-user] Ffmpeg performance issue when transcoding to webm

Fri Jun 12 13:30:57 CEST 2015

I have recently updated ffmpeg from version 2.0.2 to the most recent
release 2.7. I installed it using the same building configuration as the
old version and the same codecs version (libvpx and h264). When I tried to
transcode an mp4 video to webm, I found out that the speed of the new
version is significantly lower (3 times) than the old one. I run this on
two identical 8 core machines (Intel(R) Xeon(R) CPU E5-2680 v2 @ 2.80GHz) -
OS: Ubuntu 14.04. Below is the command I run:

/usr/local/bin/ffmpeg -i in.mp4 -f webm -vcodec libvpx -b:v 1000K out.webm

These are the outputs for the two versions:

v 2.0.2

ffmpeg version 2.0.2 Copyright (c) 2000-2013 the FFmpeg developers
built on Jan  7 2015 13:51:25 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
configuration: --disable-ffplay --disable-ffserver --enable-libxvid
--enable-gpl --enable-nonfree --enable-pthreads --enable-libmp3lame
--enable-libx264 --enable-libfaac --enable-zlib --enable-avfilter
--enable-libfreetype --enable-libfdk_aac --enable-libtheora
--enable-libvorbis --enable-libvpx --enable-pic --enable-shared
libavutil      52. 38.100 / 52. 38.100
libavcodec     55. 18.102 / 55. 18.102
libavformat    55. 12.100 / 55. 12.100
libavdevice    55.  3.100 / 55.  3.100
libavfilter     3. 79.101 /  3. 79.101
libswscale      2.  3.100 /  2.  3.100
libswresample   0. 17.102 /  0. 17.102
libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'in.mp4':
Metadata:
major_brand     : isom
minor_version   : 512
compatible_brands: isomiso2avc1mp41
encoder         : Lavf55.12.100
Duration: 00:00:10.19, start: 0.000000, bitrate: 1724 kb/s
Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p,
1280x720 [SAR 1:1 DAR 16:9], 1480 kb/s, 29.97 fps, 29.97 tbr, 90k tbn,
59.94 tbc
Metadata:
  handler_name    : VideoHandler
Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo,
fltp, 253 kb/s
Metadata:
  handler_name    : SoundHandler
[libvpx @ 0x22f3760] v1.3.0
Output #0, webm, to 'out.webm':
Metadata:
major_brand     : isom
minor_version   : 512
compatible_brands: isomiso2avc1mp41
encoder         : Lavf55.12.100
Stream #0:0(und): Video: vp8 (libvpx), yuv420p, 1280x720 [SAR 1:1 DAR
16:9], q=-1--1, 1000 kb/s, 1k tbn, 29.97 tbc
Metadata:
  handler_name    : VideoHandler
Stream #0:1(und): Audio: vorbis (libvorbis), 44100 Hz, stereo, fltp
Metadata:
  handler_name    : SoundHandler
Stream mapping:
Stream #0:0 -> #0:0 (h264 -> libvpx)
Stream #0:1 -> #0:1 (aac -> libvorbis)
Press [q] to stop, [?] for help
frame=  302 fps= 23 q=0.0 Lsize=    1445kB time=00:00:10.18
bitrate=1161.9kbits/s
video:1304kB audio:128kB subtitle:0 global headers:4kB muxing overhead 0.644833%

v 2.7

ffmpeg version 2.7 Copyright (c) 2000-2015 the FFmpeg developers
built with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
  configuration: --disable-ffplay --disable-ffserver --enable-libxvid
--enable-gpl --enable-nonfree --enable-libmp3lame --enable-libx264
--enable-libfaac --enable-zlib --enable-libass --enable-pthreads
--enable-avfilter --enable-libfreetype --enable-libfdk_aac
--enable-libtheora --enable-libvorbis --enable-libvpx --enable-pic
--enable-shared --enable-openssl
  libavutil      54. 27.100 / 54. 27.100
  libavcodec     56. 41.100 / 56. 41.100
  libavformat    56. 36.100 / 56. 36.100
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 16.101 /  5. 16.101
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.100 /  1.  2.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'in.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf56.36.100
  Duration: 00:00:10.19, start: 0.000000, bitrate: 1596 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p,
1280x720 [SAR 1:1 DAR 16:9], 1480 kb/s, 29.97 fps, 29.97 tbr, 90k tbn,
59.94 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz,
stereo, fltp, 125 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
[libvpx @ 0xfe4640] v1.3.0
Output #0, webm, to 'out.webm':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf56.36.100
    Stream #0:0(und): Video: vp8 (libvpx), yuv420p, 1280x720 [SAR 1:1
DAR 16:9], q=-1--1, 1000 kb/s, 29.97 fps, 1k tbn, 29.97 tbc (default)
    Metadata:
      handler_name    : VideoHandler
      encoder         : Lavc56.41.100 libvpx
    Stream #0:1(und): Audio: vorbis (libvorbis), 44100 Hz, stereo,
fltp (default)
    Metadata:
      handler_name    : SoundHandler
      encoder         : Lavc56.41.100 libvorbis
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> vp8 (libvpx))
  Stream #0:1 -> #0:1 (aac (native) -> vorbis (libvorbis))
Press [q] to stop, [?] for help
frame=  302 fps=8.3 q=0.0 Lsize=    1410kB time=00:00:10.18
bitrate=1133.4kbits/s
video:1274kB audio:123kB subtitle:0kB other streams:0kB global
headers:4kB muxing overhead: 0.909304%

I tried ffmpeg 2.6.3 and the performance the same as for 2.7. Also it looks
like when I transcode webm to mp4 2.7 is 30% faster than webm.

I tried to look if there are building configuration options for the new
version but couldn't find anything.

Can anyone suggest a possible reason for the worse speed performance of the
new version when transcoding to webm?

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