[FFmpeg-devel] [PATCH] avformat/mov: Add support for demuxing still HEIC images

[Andreas Rheinhardt]

Vignesh Venkat via ffmpeg-devel:
> On Tue, Oct 3, 2023 at 9:40 PM Vittorio Giovara
> <vittorio.giovara at gmail.com> wrote:
>>
>>
>>
>> On Wed, Oct 4, 2023 at 12:02 AM Vignesh Venkat via ffmpeg-devel <ffmpeg-devel at ffmpeg.org> wrote:
>>>
>>> On Tue, Oct 3, 2023 at 6:32 PM Vittorio Giovara
>>> <vittorio.giovara at gmail.com> wrote:
>>>>
>>>> On Tue, Oct 3, 2023 at 8:30 PM Steven Liu <lingjiujianke at gmail.com> wrote:
>>>>
>>>>>>> 2.42.0.515.g380fc7ccd1-goog
>>>>>>>
>>>>>>
>>>>>> Any comments/objections on merging this?
>>>>>
>>>>>
>>>>> Can this patch support tiled hevc coded or sequence heif？=
>>>>>
>>>>
>>>> I believe that will be possible only after AVStreamGroup is implemented.
>>>>
>>>
>>> Yes, this patch only supports still HEIC images that don't have alpha
>>> and grids (tiles).
>>>
>>> Tiles and Alpha support will be possible only after AVStreamGroup is
>>> implemented. I will look into HEIC sequences in a follow-up.
>>>
>>>> Vignesh is there a sample available? Could we add a test?
>>>
>>> I tested it from the files in
>>> https://github.com/nokiatech/heif/tree/gh-pages/content/images. I am
>>> not sure about HEVC licensing and if we are allowed to copy some of
>>> those files in the ffmpeg fate server. Would generating a random image
>>> with ffmpeg and encoding it as HEIC be good enough?
>>
>>
>> I would prefer a real world example and FATE has a bunch of conformance samples already.
>> Adding the ones from https://github.com/nokiatech/heif_conformance shouldn't be a problem.
>> Ideally the sample test should be added to this same patch.
> 
> Great, i have added two samples. Can you please upload C002.heic and
> C003.heic from the heif_conformance repository to the fate server
> under the "heif-conformance" sub-directory. I have also attached those
> two files in this email for reference. I will update the patch with
> the fate tests.
> 

Why are you intend to add so big files when the linked repo contains
smaller files? All five multilayer files are below 20KB each;
multilayer005.heic is even only 4.5KB. MIAF002.heic (8.6KB) and
MIAF003.heic (13.5KB) are also quite small. C025.heic (19.4KB) and
C053.heic (14.2KB) are also quite small and there are also other samples
in the 50KB-60KB range (C017.heic, C018.heic, C019.heic, C020.heic,
C041.heic). Besides taking up less diskspace, smaller files will likely
be faster to decode (which is particularly advantageous for people like
me who run FATE a lot).

- Andreas