[FFmpeg-devel] [PATCH v28] lavf/movenc: Add palette to video sample description

Mats Peterson matsp888 at yahoo.com
Fri Feb 26 23:22:24 CET 2016


Michael Niedermayer <michael at niedermayer.cc> skrev: (26 februari 2016 22:56:42 CET)
>On Fri, Feb 26, 2016 at 08:00:58AM +0100, Mats Peterson wrote:
>> On 02/26/2016 07:41 AM, Mats Peterson wrote:
>> >>Look at this snippet from libavformat/qtpalette.c that stores a
>palette
>> >>entry (palette[] is uint32_t):
>> >>
>> >>palette[i] = (a << 24 ) | (r << 16) | (g << 8) | (b);
>> >>
>> >>The way it is stored in memory is obviously dependent on the
>endianness
>> >>of the machine. For little-endian machines, it will be BGRA, and
>for
>> >>big-endian ones ARGB.
>> >>
>> >>Mats
>> >>
>> >
>> >This shouldn't have any relevance, though. Something is possibly
>wrong
>> >with the palette storage endian-wise when converting that matrix
>file
>> >from yuv420p to pal8.
>> >
>> >Mats
>> >
>> 
>> My final spam for some time. The palette is stored in host byte
>> order internally, isn't it? Then I don't understand whatsoever why
>> v26 of my movenc patch will fail on a big-endian machine. No
>> AV_RL32() should be needed.
>
>for normal AVPackets AVPacket.data should not be in some host
>endian specific format
>
>[...]

That much I understand now.
-- 
Mats Peterson
http://matsp888.no-ip.org/~mats/


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