[FFmpeg-devel] [PATCH] movenc: Force setting of "Samples per packet" field in SoundDescription V1 extended info

Michael Niedermayer michaelni at gmx.at
Tue Oct 9 00:13:46 CEST 2012


On Mon, Oct 08, 2012 at 08:15:11AM +0100, Tim Nicholson wrote:
> On 05/10/12 19:26, Michael Niedermayer wrote:
> > On Fri, Oct 05, 2012 at 06:23:11PM +0200, Michael Niedermayer wrote:
> >> On Fri, Oct 05, 2012 at 09:42:52AM +0100, Tim Nicholson wrote:
> >>> Apple spec is for this field to be always one for uncompressed PCM,
> >>> currently this is only forced for V2 Sound descriptions and left at
> >>> track->enc->frame_size for V1.
> >>>
> >>
> >>> Curiously this seems to come out at "1" for 'le' flavours anyway but
> >>> 'be' returns "0".
> >>
> >> why does the frame_size field differ between le and be ?
> >> that doesnt feel correct at all
> > 
> > the difference is caused simply by the LE fate test not using mov but
> > rather wav
> 
> Ahh. Hadn't spotted that.
> 
> Actually the inconsistency that concerns me is that for V1 descriptors
> the value is simply written from 'track->enc->frame_size', but for
> version 2 it is calculated using 'get_samples_per_packet' and which
> already forces the result of '1' for lpcm. AFAIK this atom is common to
> both V1 and version 2 descriptors so I am wondering why the difference,
> and is 'track->enc->frame_size' ever a valid figure?
> 
> > ill wait a day or 2 in case someone wants to test with common non free
> > tools if they like the more correct value, before commit
> >
> 
> I am currently running a lot of stuff through 'Baton' which seems
> particularly picky, Hence the current rash of clean ups.

ok, patch applied

thanks

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

Breaking DRM is a little like attempting to break through a door even
though the window is wide open and the only thing in the house is a bunch
of things you dont want and which you would get tomorrow for free anyway
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