[FFmpeg-devel] [PATCH 1/3] lavf/riffenc: Improve spec compliance

[Michael Niedermayer]

On Fri, Mar 11, 2016 at 03:31:55PM +0100, Mats Peterson wrote:
> On 03/11/2016 03:27 PM, Mats Peterson wrote:
> >On 03/11/2016 03:21 PM, Mats Peterson wrote:
> >>On 03/11/2016 03:13 PM, Mats Peterson wrote:
> >>>Michael Niedermayer <michael at niedermayer.cc> skrev: (11 mars 2016
> >>>15:05:49 CET)
> >>>>On Fri, Mar 11, 2016 at 02:12:56PM +0100, Mats Peterson wrote:
> >>>>>Mats Peterson <matsp888-at-yahoo.com at ffmpeg.org> skrev: (11 mars 2016
> >>>>14:06:19 CET)
> >>>>>>Mats Peterson <matsp888-at-yahoo.com at ffmpeg.org> skrev: (11 mars
> >>>>2016
> >>>>>>13:55:20 CET)
> >>>>>>>Michael Niedermayer <michael at niedermayer.cc> skrev: (11 mars 2016
> >>>>>>>13:49:32 CET)
> >>>>>>>>On Fri, Mar 11, 2016 at 01:28:47PM +0100, Mats Peterson wrote:
> >>>>>>>>>On 03/11/2016 01:25 PM, Mats Peterson wrote:
> >>>>>>>>>>On 03/11/2016 01:14 PM, Michael Niedermayer wrote:
> >>>>>>>>>>>On Fri, Mar 11, 2016 at 05:17:18AM +0100, Mats Peterson wrote:
> >>>>>>>>>>>>On 03/11/2016 05:10 AM, Mats Peterson wrote:
> >>>>>>>>>>>>>Forget patch 2/3 and 3/3 from the old patch set.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> From the Microsoft documentation for BITMAPINFOHEADER at
> >>>>>>>>>
> >>>>>
> >>>>>>>>>>>https://msdn.microsoft.com/en-us/library/windows/desktop/dd318229%28v=vs.85%29.aspx:
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>"biSize: Specifies the number of bytes required by the
> >>>>>>>structure.
> >>>>>>>>This
> >>>>>>>>>>>>>value does not include the size of the color table or the
> >>>>size
> >>>>>>>of
> >>>>>>>>the
> >>>>>>>>>>>>>color masks, if they are appended to the end of structure."
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>So, biSize is always 40. Also, Windows Media Player won't
> >>>>>>detect
> >>>>>>>>video
> >>>>>>>>>>>>>encoded with Microsoft Video 1 in 8 bpp mode if this value
> >>>>is
> >>>>>>>>anything
> >>>>>>>>>>>>>else than 40. I don't know about other codecs, they probably
> >>>>>>>>work.
> >>>>>>>>>>>>>Anyway, we should stick with the specs, and not include the
> >>>>>>>>palette
> >>>>>>>>>>>>>size
> >>>>>>>>>>>>>in that field.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>Regarding the biClrUsed field, I'm setting it to 1 <<
> >>>>>>>>>>>>>bits_per_coded_sample if palettized video, since setting it
> >>>>to
> >>>>>>0
> >>>>>>>>is
> >>>>>>>>>>>>>another case where it won't work with Windows Media Player
> >>>>and
> >>>>>>>>>>>>>Microsoft
> >>>>>>>>>>>>>Video 1 in 8 bpp mode.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>Mats
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>Once, again, HuffYUV has its own variant of BITMAPINFOHEADER
> >>>>>>that
> >>>>>>>>>>>>*does* include the size of the Huffman tables in biSize.
> >>>>That's
> >>>>>>>>the
> >>>>>>>>>>>>only exception as far as I know.
> >>>>>>>>>>>
> >>>>>>>>>>>is huffyuv really the exception ? and not raw rgb or palettes
> >>>>?
> >>>>>>>>>>>
> >>>>>>>>>>>asv1 and asv2 do not have 40 there
> >>>>>>>>
> >>>>>>>>>>>which codec with a non-palette global header puts 40 there ?
> >>>>>>>>
> >>>>>>>>[...]
> >>>>>>>>
> >>>>>>>>>As I said before, Microsoft Video 1 in 8-bit mode and RLE4/RLE8
> >>>>>>>>>won't even display in Windows Media Player if this value is
> >>>>>>anything
> >>>>>>>>>else than 40.
> >>>>>>>>
> >>>>>>>>msv1 / RLE4/8 doesnt have a "Non palette global header"
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>[...]
> >>>>>>>
> >>>>>>>That's correct. Sorry. Anyway, the only case I know of is HuffYUV
> >>>>with
> >>>>>>>its special variant of BITMAPINFOHEADER that includes the Huffman
> >>>>>>>tables. Is there stated anywhere in the ASUS specs that the size of
> >>>>>>the
> >>>>>>>extra data following the BITMAPINFOHEADER should be included in
> >>>>>>biSize?
> >>>>>>>If not, it should be 40.
> >>>>>>>
> >>>>>>>Mats
> >>>>>>>--
> >>>>>>>Mats Peterson
> >>>>>>>http://matsp888.no-ip.org/~mats/
> >>>>>>>_______________________________________________
> >>>>>>>ffmpeg-devel mailing list
> >>>>>>>ffmpeg-devel at ffmpeg.org
> >>>>>>>http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >>>>>>
> >>>>>>Those asv1/asv2 files play just fine with a biSize of 40, at that.
> >>>>>>
> >>>>>>Mats
> >>>>>>--
> >>>>>>Mats Peterson
> >>>>>>http://matsp888.no-ip.org/~mats/
> >>>>>>_______________________________________________
> >>>>>>ffmpeg-devel mailing list
> >>>>>>ffmpeg-devel at ffmpeg.org
> >>>>>>http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >>>>>
> >>>>>Should we perhaps "tighten" the "specs" (I saw that you have written
> >>>>some documentation on asv1/asv2 in FFmpeg), and include those extra
> >>>>bytes in biSize? I suppose this is somewhat of a proprietary FFmpeg
> >>>>invention.
> >>>>
> >>>>we didnt invent ASUS video 1 and 2 nor huffyuv
> >>>>
> >>>>which codec with a non-palette global header puts 40 there ?
> >>>>
> >>>>the ms specs just says the color table & mask isnt part of biSize
> >>>>it doesnt say the global header isnt, or iam looking at the wrong text
> >>>>or location in the text/spec
> >>>>
> >>>>[...]
> >>>
> >>>Again, only one I know of is HuffYUV, and the specs define a custom
> >>>BITMAPINFOHEADER that includes the Huffman tables. The "global data"
> >>>in ASUS is only 8 bytes. Do they regard the BITMAPINFOHEADER as being
> >>>part of this global data as well? And should we? A BITMAPINFOHEADER is
> >>>a BITMAPINFOHEADER is a BITMAPINFOHEADER...
> >>>
> >>>Mats
> >>>
> >>
> >>Do you have a sample file with asv1/asv2 *created by ASUS* where biSize
> >>isn't 40?
> >>
> >>Mts
> >>
> >
> >I got the asv1/asv2 samples from the MPlayer sample directory. Are they
> >from ASUS? They all use a biSize of 48.
> >
> >Mats
> >
> 
> Nope. Written with libavformat.

why do you think they are written by libavformat ?

i see:
"C:\PROGRAM FILES\ASUS\ASUS LIVE\ASUSLIVE.EXE -AVICAP32- ASUS Video Capture Driver, Version:  3.8.2.2"

in asv2_320x240_3.avi


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

Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety -- Benjamin Franklin
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