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| trodas |
Posted: Mar 14 2013, 09:06 PM |
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Advanced Member
  
Group: Members
Posts: 88
Member No.: 22291
Joined: 22-October 07

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I would like to point out something at least odd, but maybe it is a bug. Usually, I need to export audio from many videos (to normalize it, etc.). Usualy works the Save WAV to save, well, not a WAV, yet a decodable data, witch using FFmpeg can be comverted to WAV and worked with later. In some cases I used the Export raw audio option, but usually everything works. Untill this video: http://www.moonfaker.com/videos4mirror/Re_...oax_Not.wmv.zip
When I saved the audio (raw as x.bit, "Save WAV" as x.wma) using VirtualDub, I cannot decode it using FFmpeg (latest):
| QUOTE | D:\Tools\Lame>ffmpeg -i x.wma -vn -f wav x.wav ffmpeg version N-50880-gc3bb2f7 Copyright © 2000-2013 the FFmpeg developers built on Mar 13 2013 17:56:41 with gcc 4.4.4 (GCC) (x86.generic.Komisar) configuration: --disable-w32threads libavutil 52. 19.100 / 52. 19.100 libavcodec 55. 0.100 / 55. 0.100 libavformat 55. 0.100 / 55. 0.100 libavdevice 54. 4.100 / 54. 4.100 libavfilter 3. 45.101 / 3. 45.101 libswscale 2. 2.100 / 2. 2.100 libswresample 0. 17.102 / 0. 17.102 [wav @ 0191f380] no 'data' tag found x.wma: Invalid data found when processing input
D:\Tools\Lame>ffmpeg -i x.bin -vn -f wav x.wav ffmpeg version N-50880-gc3bb2f7 Copyright © 2000-2013 the FFmpeg developers built on Mar 13 2013 17:56:41 with gcc 4.4.4 (GCC) (x86.generic.Komisar) configuration: --disable-w32threads libavutil 52. 19.100 / 52. 19.100 libavcodec 55. 0.100 / 55. 0.100 libavformat 55. 0.100 / 55. 0.100 libavdevice 54. 4.100 / 54. 4.100 libavfilter 3. 45.101 / 3. 45.101 libswscale 2. 2.100 / 2. 2.100 libswresample 0. 17.102 / 0. 17.102 [NULL @ 01946380] [IMGUTILS @ 0022f424] Picture size 1280x917072 is invalid [NULL @ 01946380] Ignoring invalid width/height values [bintext @ 01946380] Warning: not compiled with thread support, using thread emu lation [bintext @ 01946380] [IMGUTILS @ 0022f234] Picture size 0x0 is invalid [bintext @ 01946380] video_get_buffer: image parameters invalid [bintext @ 01946380] get_buffer() failed [bin @ 0191f3a0] Stream #0: not enough frames to estimate rate; consider increas ing probesize [bin @ 0191f3a0] decoding for stream 0 failed [bin @ 0191f3a0] Could not find codec parameters for stream 0 (Video: bintext, p al8): unspecified size Consider increasing the value for the 'analyzeduration' and 'probesize' options [bin @ 0191f3a0] Estimating duration from bitrate, this may be inaccurate x.bin: could not find codec parameters |
Of course, I can much easier extract the audio using FFmpeg completely: ffmpeg -i x.wmv x.wav
...and it works just perfectly.
Cases in point - exporting wma v2 audio somewhat not work at all. - saving WAV never produce actually a WAV and also did not work correctly when using wma v2 audio
FFmpeg is open source and the code that save the audio well can be borrowed from it easily 
PS. I have a suggestion to make. After seeing some videos on YewTube, that emphasise choosing the setting "Video:Direct strem copy" - http://www.youtube.com/watch?v=lz8pZtk_ATE - how about to make this a default? Just for the simplier part of the users, lol. So that they not end up with crazy huge videos, so.... That should not hurt anyone?
-------------------- "It is dangerous to be right in matters on which the established authorities are wrong." - Voltaire ...just keep folding, just keep folding... :) my config - my caps |
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| phaeron |
| Posted: Mar 17 2013, 02:09 AM |
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Virtualdub Developer
  
Group: Administrator
Posts: 7773
Member No.: 61
Joined: 30-July 02

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Using the Save WAV command to produce a .wma file is bogus. WAV files can be compressed, and so that's what you're getting; however, not all programs can deal with this, and in your case you're likely relying on some scanning logic in FFMpeg that isn't guaranteed to be able to skip past the WAV header reliably. If what you want is an uncompressed PCM WAV file, change the audio mode. If you want raw data, use the Export Raw Audio command. |
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| Abrazo |
| Posted: Mar 17 2013, 10:16 AM |
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Advanced Member
  
Group: Members
Posts: 775
Member No.: 28995
Joined: 5-November 10

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@trodas
I do not know what your final goal may be, but I do not see any problem to export whatever audio from within VirtualDub directly to a WAV by this method: > Set the Audio menu to Full processing mode > Set Audio > Compression... to "<No compression (PCM)>" > Set Audio > Conversion... > Sampling / Precision / Channels / High quality, to whatever you want > File > Save WAV...
In this manner you can even transform or "convert" the audio directly into another codec-format, by: > setting Audio > Compression... to for exemple MPEG Layer-3 > File > Save WAV...
I did a few tests with your sample video : no problem at all.
It is only when leaving Audio-menu to "Direct Stream Copy" that you extract the original audio out of the movie and that you will get an audio-file that you maybe cannot read with another program. |
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| trodas |
Posted: Mar 18 2013, 10:57 AM |
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Advanced Member
  
Group: Members
Posts: 88
Member No.: 22291
Joined: 22-October 07

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phaeron - you are right, usually it works, but not all the time, sadly I have to pay more attention to the VirtualDub settings.
Abrazo - thanks a lot for the explaination. I never come to realize, that what I choose VirtualDub to do in the Audio menu settings does apply to even the Save WAV function, witch I - to this day - seen as independent function that have really no connection to anything... I was dead wrong. And now I feel ashamed that I did not come to this conclusion sooner. In fact, I did not need FFmpeg now at all, since VirtualDub can and do save WAV perfectly...
Mea culpa.
-------------------- "It is dangerous to be right in matters on which the established authorities are wrong." - Voltaire ...just keep folding, just keep folding... :) my config - my caps |
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