Re: Controlling the Pixel Aspect Ratio (PAR)

On Mon, Mar 14, 2011 at 01:39:36PM -0400, Tony Strauss wrote:
> I originally posted this to ffmpeg-user, but I'm now contemplating
> writing a patch:
> I need to break videos up into frames (.tga, TARGA format frames).
> These videos are uploaded by users and can come in a variety of
> formats.  I can accomplish this with a command like:
> ffmpeg -i movie.wmv -r 24 -f image2 images%05d.tga
> 
> I run into issues, however, when the pixel aspect ratio (PAR) of a
> movie is not 1:1.  For example, a movie with a resolution of
> 1440x1080, a PAR of 4:3, and thus an aspect resolution (DAR) of 16:9
> results in incorrect .tga frames.  The frames have resolution
> 1440x1080 and a PAR of 1:1.  It's not clear whether ffmpeg's .tga
> encoder understands pixel aspect resolution, but, in any case, I need
> frames with a pixel aspect ratio of 1:1 for my purposes.  As far as I
> can tell, the only way to force ffmpeg to encode the frames with a PAR
> of 1:1 is to specify the frame resolution.

get latest ffmpeg git
use -vf setsar=1

[...]

--

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Avoid a single point of failure, be that a person or equipment.

_______________________________________________

Re: [PATCH]Plausibility check for TrueHD channel_layout

On Thu, Mar 31, 2011 at 10:32:13PM +0000, Carl Eugen Hoyos wrote:
> Michael Niedermayer <michaelni <at> gmx.at> writes:
> 
> > > +            if (av_popcount(avctx->channel_layout) != avctx->channels) {
> > > +                avctx->channel_layout = 0;
> > > +                av_log_ask_for_sample(avctx, "Unknown channel layout.");
> > > +            }
> > >          }
> > 
> > i think this shoulds be a if() level further outside
> 
> The condition can only be true for TrueHD streams, or do I miss something?

If the other code is never changed, yes
i had not noticed that so IMHO either placement is ok

[...]
--

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

You can kill me, but you cannot change the truth.

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel <at> ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel

xvYCC Conversion to Wide Gamut RGB with FFmpeg

Is it possible to convert xvYCC to wide gamut RGB using FFmpeg?

Is it possible to specify a high precision 3D LUT as tool for conversion?

Such as the open specification of described here
http://yesgrey.com/ycms.html and discussed on the forum at Doom9.

My query is based on the understanding rightly or wrongly that a typical
conversion to RGB uses only the 16 - 235 & 240 chroma range and that this
relates to sRGB gamut. That xvYCC gamut is potentially 1.8 times wider and
that a wide RGB gamut such as AdobeRGB is required to 'hold' the converted
data to do a 'proper' conversion.

Re: xvYCC Conversion to Wide Gamut RGB with FFmpeg

On Fri, Apr 01, 2011 at 06:45:07AM +0100, yellowsblog wrote:
> Is it possible to convert xvYCC to wide gamut RGB using FFmpeg?
> 
> Is it possible to specify a high precision 3D LUT as tool for conversion?

If you implement these things and send us a patch then it is possible

[...]
--
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

He who knows, does not speak. He who speaks, does not know. -- Lao Tsu

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel <at> ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel

x11grab.c: minor clean up, added more documentation

Hello,

I hope you find this appropriate.

Sven

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel <at> ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel

Re: x11grab.c: minor clean up, added more documentation

Sven C. Dack <sven.c.dack <at> virginmedia.com> writes:

> -    char *param, *offset;
> +    char *dpyname, *offset;

If the variable renaming is necessary, it should be in a separate patch.

> -    param = av_strdup(s1->filename);
> -    offset = strchr(param, '+');
> +    dpyname = av_strdup(s1->filename);
> +    x11grab->dpyname = dpyname;
> +    
> +    offset = strchr(dpyname, '+');

... making this diff significantly smaller.

>      if (offset) {
>          sscanf(offset, "%d,%d", &x_off, &y_off);
> -        x11grab->nomouse= strstr(offset, "nomouse");
> -        *offset= 0;
> +        x11grab->nomouse = strstr(offset, "+nomouse") == NULL ? 0 : 1;
> +        *offset = '\0';

If I understand it correctly, this change is definitely not appropriate.

>      }
> 
> -    av_log(s1, AV_LOG_INFO, "device: %s -> display: %s x: %d y: %d width: %d
height: %d\n", s1->filename,
> param, x_off, y_off, ap->width, ap->height);

Re: x11grab.c: minor clean up, added more documentation

On 01/04/11 11:13, Carl Eugen Hoyos wrote:
> Sven C. Dack<sven.c.dack<at>  virginmedia.com>  writes:
>
>    
>> -    char *param, *offset;
>> +    char *dpyname, *offset;
>>      
> If the variable renaming is necessary, it should be in a separate patch.
>
>    
>> -    param = av_strdup(s1->filename);
>> -    offset = strchr(param, '+');
>> +    dpyname = av_strdup(s1->filename);
>> +    x11grab->dpyname = dpyname;
>> +
>> +    offset = strchr(dpyname, '+');
>>      
> ... making this diff significantly smaller.
>
>    
>>       if (offset) {
>>           sscanf(offset, "%d,%d",&x_off,&y_off);
>> -        x11grab->nomouse= strstr(offset, "nomouse");
>> -        *offset= 0;
>> +        x11grab->nomouse = strstr(offset, "+nomouse") == NULL ? 0 : 1;
>> +        *offset = '\0';
>>      
> If I understand it correctly, this change is definitely not appropriate.
>
>    

Re: xvYCC Conversion to Wide Gamut RGB with FFmpeg

On Fri, 1 Apr 2011 06:45:07 +0100, yellowsblog wrote:
>Is it possible to convert xvYCC to wide gamut RGB using FFmpeg?

not currently.

could you upload a sample of this xvycc somewhere?

-compn

Re: [PATCH] support for flvtool2 "keyframes based" generated index in FLV format decoder

Hi

On Thu, Mar 03, 2011 at 11:35:27AM +0600, Kharkov Alexander wrote:
> Can someone review and probably apply the patch?

Iam sorry for the delay, the patch has been applied with cleanups
to ffmpeg.

[...]
--

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The bravest are surely those who have the clearest vision
of what is before them, glory and danger alike, and yet
notwithstanding go out to meet it. -- Thucydides

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel <at> ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel

Re: xvYCC Conversion to Wide Gamut RGB with FFmpeg

My understanding is that any YCbCr source with captured data in range
outside 16 - 235/240 and sRGB colour primaries may well be xvYCC or at the
very least have colour information beyond sRGB gamut, so I can give you a
link to a h264AVC .MOV source shot from a Canon HD DSLR and a discussion
thread on Doom9:

Link to file:

http://www.yellowspace.webspace.virginmedia.com/Gold.aMOV

Link to Discussion:

http://forum.doom9.org/showthread.php?t=159915

The thread also discusses yCMS 3D LUT system which has recently had xvYCC
support added.

On 1 April 2011 12:10, compn <tempn <at> twmi.rr.com> wrote:

> On Fri, 1 Apr 2011 06:45:07 +0100, yellowsblog wrote:
> >Is it possible to convert xvYCC to wide gamut RGB using FFmpeg?
>
> not currently.
>
> could you upload a sample of this xvycc somewhere?
>
> -compn
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel <at> ffmpeg.org