[Ffmpeg-devel] closed captioning bug?

Cyrus A lists
Thu May 4 00:45:27 CEST 2006

Luca Abeni wrote:
> Hi,
> On Fri, 2006-04-28 at 15:30 -0400, Cyrus A wrote:
>> The audio seems broken now.
>> I upgraded the AMD 64 X2 system to FC4, downloaded the latest CVS, 
>> applied the v4l2 patch and ran a test.
>> The video looks nice, the captions are fine, but there is no sound. I 
>> can confirm with 100% certainty that sound on my system and audio device 
>> DOES work since trying the EXACT same ffmpeg command on a different 
>> build has sound. Plus, I noticed the same behavior when the patch was 
>> applied to CVS build of ffmpeg on an i386 FC5 machine I own as well.
>> Why do you think the audio is now broken?
> This is difficult to tell... I have never seen such problem: I suspect
> it might depend on some specific hardware issue that I've never been
> able to reproduce.
> The "v4l2-fedora.diff" patch simply allowed configure to detect
> video4linux2, and I cannot understand how it can influence the audio...
> Before going on, can you check if the mixer settings are ok?
> (does /dev/dsp work? - Note that the system could see 2 audio cards:
> maybe ffmpeg is capturing from the wrong one?)
> Anyway, to be able to give some more hints I need:
> 1) the config.h and config.mak files (generated by configure)
> 2) the full output of the ffmpeg command you ran
> 3) the output when you add "-d 5" to the command line
> 			Thanks,
> 				Luca
I've already wiped the machine and attempted to downgrade to an i386 
setup. (now I'm stuck trying to get 4x SATA drives recognized through a 
promise RAID controller... ugh) However, I do remember that it HAD to be 
a problem with ffmpeg/v4l2 since no audio was coming out of the video 
card. Usually I run an audio cable from the TV capture card into the 
line-in of a sound device. When that didn't work, I plugged my 
headphones directly into the card itself. Nothing there. When I used an 
unpatched ffmpeg version, the audio was fine -- both directly out of the 
bttv card and through the sound device.

Sorry, don't have config.h, the output or the -d 5 output. If I 
re-install FC5 and try again, I'll be sure to post it.


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