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

[Mats Peterson]

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.

Mats

-- 
Mats Peterson
http://matsp888.no-ip.org/~mats/