[MPlayer-users] Cannot record audio from tv tuner.

Andy Furniss adf.lists at gmail.com
Tue Aug 12 22:36:46 CEST 2014


Marc MERLIN wrote:

> On Tue, Aug 12, 2014 at 06:33:42PM +0100, Andy Furniss wrote:
>> It's many years since I ripped from tape but to get 422 from my
>> card I used planar outfmt=yuy2.
>>
>> The only reason I used 422 was that I wanted to use dv50 as an
>> intermediate format (it was the best my PC at the time could do).
>>
>> I don't think PAL is 422 to start with - so if you don't have a
>> specific need it would easier to ask the card for 420 eg, yv12.
>>
>> There should be a way to query the card/v4l2 for supported formats
>> like v4linfo - maybe mplayer/mencoder with -v will give extra info
>> (maybe not - it was years ago).
>
> Thanks for pointing out v4l-info. It says: video capture
> VIDIOC_ENUM_FMT(0,VIDEO_CAPTURE) index                   : 0 type
> : VIDEO_CAPTURE flags                   : 0 description             :
> "16bpp YUY2, 4:2:2, packed" pixelformat             : 0x56595559
> [YUYV] VIDIOC_G_FMT(VIDEO_CAPTURE) type                    :
> VIDEO_CAPTURE fmt.pix.width           : 720 fmt.pix.height          :
> 576 fmt.pix.pixelformat     : 0x56595559 [YUYV] fmt.pix.field
> : INTERLACED fmt.pix.bytesperline    : 1440 fmt.pix.sizeimage       :
> 829440 fmt.pix.colorspace      : SMPTE170M fmt.pix.priv            :
> 0
>
>> Using 422 for interlaced content can result in extra scope for
>> errors when converted to 420.
>
> Per your suggestions, I've switched from outfmt=uyvy to outfmt=yuy2
> I'm not sure i fI see a difference, but I guess that can't hurt :)

There should be no visible difference - I just suggested yuy2 in case it
was the uyvy that was causing the problem - re-reading I see you said
that worked anyway.

The v4l-info shows that the device only does 422 variants, so if you do
get it working and want to convert to something that needs 420 like dvd
and the content is interlaced and you want to retain it interlaced you
will need to be careful to specify that it is interlaced to mencoder or
ffmpeg, with ffmpeg this means you can't use -target pal-dvd.




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