[FFmpeg-user] crf mode in libvpx

[Boštjan Strojan]

> What did you try? Doesn't -qscale / -vq work?

Thanks, but nope they don't seem to do anything. No errors are
reported, i guess switches are just silently ignored.

example:
----------------ffmpeg -i /Users/smoke/Desktop/test.mov  -strict -2
-acodec vorbis -b:a 64k -qscale 30 -q:v 0 -vcodec libvpx
./Desktop/test.webm
ffmpeg version N-37510-g8c48652 Copyright (c) 2000-2012 the FFmpeg developers
  built on Feb  2 2012 22:02:52 with clang 3.0 (tags/Apple/clang-211.12)
  configuration: --prefix=/Volumes/tempdisk/sw --enable-gpl
--enable-libx264 --enable-libvpx --cc=clang --enable-runtime-cpudetect
  libavutil      51. 37.100 / 51. 37.100
  libavcodec     54.  0.102 / 54.  0.102
  libavformat    54.  0.100 / 54.  0.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 61.100 /  2. 61.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  6.100 /  0.  6.100
  libpostproc    52.  0.100 / 52.  0.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fd32b81ae00] decoding for stream 2 failed
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Users/smoke/Desktop/test.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 537199360
    compatible_brands: qt
    creation_time   : 2012-02-01 08:54:28
  Duration: 00:00:15.00, start: 0.000000, bitrate: 738837 kb/s
    Stream #0:0(eng): Video: r10k (R10g / 0x67303152), rgb48le,
1280x720, 737280 kb/s, SAR 1280:1280 DAR 16:9, 25 fps, 25 tbr, 25 tbn,
25 tbc
    Metadata:
      creation_time   : 2012-02-01 08:54:28
      handler_name    : ?Apple Alias Data Handler
    Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz,
stereo, s16, 1536 kb/s
    Metadata:
      creation_time   : 2012-02-01 08:54:28
      handler_name    : ?Apple Alias Data Handler
    Stream #0:2(eng): Data: none (tmcd / 0x64636D74)
    Metadata:
      creation_time   : 2012-02-01 08:54:59
      handler_name    : ?Apple Alias Data Handler
      timecode        : 00:00:00:00
Please use -q:a or -q:v, -qscale is ambiguous
Incompatible pixel format 'rgb48le' for codec 'libvpx', auto-selecting
format 'yuv420p'
[buffer @ 0x105d15d20] w:1280 h:720 pixfmt:rgb48le tb:1/1000000
sar:1280/1280 sws_param:
[buffersink @ 0x105d16ec0] auto-inserting filter 'auto-inserted scale
0' between the filter 'src' and the filter 'out'
[scale @ 0x105d172a0] w:1280 h:720 fmt:rgb48le -> w:1280 h:720
fmt:yuv420p flags:0x4
[libvpx @ 0x7fd32b82d000] v1.0.0
Output #0, webm, to './Desktop/test.webm':
  Metadata:
    major_brand     : qt
    minor_version   : 537199360
    compatible_brands: qt
    creation_time   : 2012-02-01 08:54:28
    encoder         : Lavf54.0.100
    Stream #0:0(eng): Video: vp8, yuv420p, 1280x720 [SAR 1:1 DAR
16:9], q=-1--1, 200 kb/s, 1k tbn, 25 tbc
    Metadata:
      creation_time   : 2012-02-01 08:54:28
      handler_name    : ?Apple Alias Data Handler
    Stream #0:1(eng): Audio: vorbis, 48000 Hz, stereo, s16, 64 kb/s
    Metadata:
      creation_time   : 2012-02-01 08:54:28
      handler_name    : ?Apple Alias Data Handler
Stream mapping:
  Stream #0:0 -> #0:0 (r10k -> libvpx)
  Stream #0:1 -> #0:1 (pcm_s16le -> vorbis)
Press [q] to stop, [?] for help
frame=   22 fps=  0 q=0.0 size=       4kB time=00:00:00.00 bitrate=
0.0kbits/sframe=   28 fps= 27 q=0.0 size=       4kB time=00:00:00.08
bitrate= 358.0kbits/sframe=   39 fps= 25 q=0.0 size=      36kB
time=00:00:00.60 bitrate= 487.6kbits/sframe=   50 fps= 23 q=0.0 size=
    36kB time=00:00:01.04 bitrate= 281.3kbits/sframe=   59 fps= 22
q=0.0 size=      36kB time=00:00:01.34 bitrate= 217.7kbits/sframe=
60 fps= 19 q=0.0 size=      36kB time=00:00:01.36 bitrate=
214.3kbits/sframe=   64 fps= 17 q=0.frame=   73 fps= 15 q=0.0 size=
 157kB time=00:00:01.96 bitrframe=  375 fps= 14 q=0.0 Lsize=    1051kB
time=00:00:15.00 bitrate= 574.1kbits/s
video:1005kB audio:35kB global headers:3kB muxing overhead 0.765023%

(crappy quality, no sound)