[FFmpeg-devel] [PATCH v9] lavc/rawdec: Remove monowhite switching code for 1 bpp AVI without a palette

[Mats Peterson]

On 02/13/2016 01:03 PM, Mats Peterson wrote:
> On 02/13/2016 01:00 PM, Mats Peterson wrote:
>> On 02/13/2016 12:58 PM, Mats Peterson wrote:
>>> On 02/13/2016 12:57 PM, Mats Peterson wrote:
>>>> On 02/13/2016 12:54 PM, Mats Peterson wrote:
>>>>> On 02/13/2016 12:52 PM, Mats Peterson wrote:
>>>>>>>> just double checked, this is not the case in written pal8 nut files
>>>>>>>> nor does the nut spec say anything about that.
>>>>>>>>
>>>>>>>
>>>>>>> Then check an odd-width nut file like the one below. And FFmpeg
>>>>>>> doesn't
>>>>>>> care about specs when using "-vcodec copy". The stride will be the
>>>>>>> one
>>>>>>> of the original data, whether it's 2, 4 or some other amount of
>>>>>>> bytes.
>>>>>>>
>>>>>
>>>>> The stride will be *aligned* to 2, 4 or some other amount of bytes.
>>>>>
>>>>> Mats
>>>>>
>>>>
>>>> Try "ffmpeg -i 8bpp_129.avi -vcodec rawvideo 8bpp_129.nut" with the
>>>> file
>>>> below. It will have a stride aligned to 4 bytes like the original AVI
>>>> file, and per the Microsoft specification, since it doesn't "-vcodec
>>>> copy" won't touch the video data.
>>>>
>>>> https://drive.google.com/open?id=0B3_pEBoLs0faekxWUTdkVGNTTlk
>>>> _______________________________________________
>>>
>>> I mean "ffmpeg -i 8bpp_129.avi -vcodec copy 8bpp_129.nut" of course.
>>>
>>> Mats
>>>
>>
>> The stride will be 132 bytes, divisible by 4, rather than 129 bytes.
>>
>> Mats
>>
>
> Now the problem is that it won't show any video, since the incorrect
> codec tag RGB[15] will be written to the nut file, and it's not possible
> to use "-vtag" to set tha PAL[8] codec tag, but if you use "-v debug"
> you will see that the stride is 132 bytes.
>
> Mats
>
> _______________________________________________

What's more, no palette will be included in the frames, since "-vcodec 
copy" once again doesn't touch the original AVI data. So it's pretty 
useless to use "-vcodec copy" for pal8.

Mats