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Re: [MPlayer-dev-eng] MPlayer and raw video




On 02/25/2016 06:12 PM, Reimar Döffinger wrote:
On Thu, Feb 25, 2016 at 08:13:25AM +0100, Mats Peterson wrote:
Since there for some reason hasn't been any response to my previous posting,
here we go again:

Well, this list is for development and patches.
Bug reports belong on either -users or the bug tracker.

Already filed.


MPlayer naively assumes that 'rawvideo' raw video from libavcodec (whether
it's contained in AVI, QuickTime or something else) contains 24-bit RGB
triplets.

No, not really.


Yes it does. Check the error messages when playing the files. It will complain at the packet size being too small, which is clearly an indication that it thinks it should be 24-bit RGB when it is in fact something much less than that.


What's more, MPlayer misinterprets a negative height in the BITMAPINFOHEADER
for AVI files as being a very large unsigned value, rather than the
indication of the video data being arranged top-to-bottom rather than
bottom-to-top.

My information is that negative values are very much not permitted
in AVI, even though it usually works when things go through the VFW
pipeline.
It's also possible that uncompressed formats would allow it though.
-demuxer lavf accepts it, but I don't think it works really properly
either.


They are permitted. Read the Microsoft documentation on BITMAPINFOHEADER. And FFmpeg uses it correctly, since it stores the image data top-down for raw video.

The files below with raw video will play without video in MPlayer.

There is (ok, rather was) simply no 2 bpp or 4 bpp support in MPlayer.
The mov issue was a rather special case in part due to lavf not doing
things in a way that is nice to us and our native demuxer not supporting
those paletted raw formats at all.


I see. Does that mean you won't support in the future? FFplay plays these files just fine, so I don't see why MPlayer shouldn't be able to play this rudimentary type of video as well.

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