Bien, el problema era el programa flv2mpeg que estaba fallando. (Que por cierto tiene otras fallas que ya he reportado)
He probado con ffmpeg y todo va de maravilla, el problema es que flv2mpeg perdia la capa de audio, y con ffmpeg no esta ese problema:
Anon@localhost % youtube-dl "http://www.youtube.com/watch?v=FeWBoADvKd4"
[youtube] FeWBoADvKd4: Downloading video webpage
[youtube] FeWBoADvKd4: Extracting video information
[youtube] FeWBoADvKd4: URL: http://www.youtube.com/get_video?video_id=FeWBoADvKd4&t=vjVQa1PpcFNSnfwxHUvvujjsX0htrs8Jr8LfQJOgr2w=
[download] Destination: FeWBoADvKd4.flv
[download] 100.0% of 1.49M at 13.02k/s ETA 00:00
Anon@localhost % ~/local/bin/ffmpeg -i FeWBoADvKd4.flv
FFmpeg version SVN-r14424, Copyright (c) 2000-2008 Fabrice Bellard, et al.
built on Mar 23 2009 00:36:11, gcc: 4.2.1 20070719 [FreeBSD]
Seems stream 0 codec frame rate differs from container frame rate: 1000.00 (1000/1) -> 30.00 (30/1)
Input #0, flv, from 'FeWBoADvKd4.flv':
Duration: 00:00:39.90, start: 0.000000, bitrate: 64 kb/s
Stream #0.0: Video: flv, yuv420p, 320x238, 30.00 tb(r)
Stream #0.1: Audio: mp3, 22050 Hz, mono, 64 kb/s
Must supply at least one output file
Anon@localhost % ~/local/bin/ffmpeg -i FeWBoADvKd4.avi
FFmpeg version SVN-r14424, Copyright (c) 2000-2008 Fabrice Bellard, et al.
built on Mar 23 2009 00:36:11, gcc: 4.2.1 20070719 [FreeBSD]
Input #0, avi, from 'FeWBoADvKd4.avi':
Duration: 00:00:40.96, start: 0.000000, bitrate: 226 kb/s
Stream #0.0: Video: mpeg4, yuv420p, 320x238 [PAR 1:1 DAR 160:119], 30.00 tb(r)
Must supply at least one output file
Despues de realizar la conversion con ffmpeg vemos que ahora si tiene la capa de audio:
Anon@localhost % ~/local/bin/ffmpeg -i FeWBoADvKd4.flv -sameq -y FeWBoADvKd4.avi
FFmpeg version SVN-r14424, Copyright (c) 2000-2008 Fabrice Bellard, et al.
built on Mar 23 2009 00:36:11, gcc: 4.2.1 20070719 [FreeBSD]
Seems stream 0 codec frame rate differs from container frame rate: 1000.00 (1000/1) -> 30.00 (30/1)
Input #0, flv, from 'FeWBoADvKd4.flv':
Duration: 00:00:39.90, start: 0.000000, bitrate: 64 kb/s
Stream #0.0: Video: flv, yuv420p, 320x238, 30.00 tb(r)
Stream #0.1: Audio: mp3, 22050 Hz, mono, 64 kb/s
Output #0, avi, to 'FeWBoADvKd4.avi':
Stream #0.0: Video: mpeg4, yuv420p, 320x238, q=2-31, 200 kb/s, 30.00 tb(c)
Stream #0.1: Audio: mp2, 22050 Hz, mono, 64 kb/s
Stream mapping:
Stream #0.0 -> #0.0
Stream #0.1 -> #0.1
Press [q] to stop encoding
frame= 1197 fps=246 q=0.0 Lsize= 4376kB time=39.90 bitrate= 898.5kbits/s
video:4008kB audio:312kB global headers:0kB muxing overhead 1.303120%
Anon@localhost % ~/local/bin/ffmpeg -i FeWBoADvKd4.avi
FFmpeg version SVN-r14424, Copyright (c) 2000-2008 Fabrice Bellard, et al.
built on Mar 23 2009 00:36:11, gcc: 4.2.1 20070719 [FreeBSD]
Input #0, avi, from 'FeWBoADvKd4.avi':
Duration: 00:00:39.91, start: 0.000000, bitrate: 898 kb/s
Stream #0.0: Video: mpeg4, yuv420p, 320x238 [PAR 1:1 DAR 160:119], 30.00 tb(r)
Stream #0.1: Audio: mp2, 22050 Hz, mono, 64 kb/s
Must supply at least one output file
Saludos