[FFmpeg-devel] [PATCH] lavf/img2: add support to IFF images sequences

[Paul B Mahol]

On 10/25/12, Tomas Haerdin <tomas.hardin at codemill.se> wrote:
> On Wed, 2012-10-24 at 13:03 +0000, Paul B Mahol wrote:
>> On 10/24/12, Stefano Sabatini <stefasab at gmail.com> wrote:
>> > Should address trac ticket #661, not tested.
>> > ---
>> >  libavformat/img2.c |    2 ++
>> >  1 files changed, 2 insertions(+), 0 deletions(-)
>> >
>> > diff --git a/libavformat/img2.c b/libavformat/img2.c
>> > index 3867477..af83e74 100644
>> > --- a/libavformat/img2.c
>> > +++ b/libavformat/img2.c
>> > @@ -29,6 +29,8 @@ typedef struct {
>> >  } IdStrMap;
>> >
>> >  static const IdStrMap img_tags[] = {
>> > +    { AV_CODEC_ID_IFF_ILBM  , "iff"},
>> > +    { AV_CODEC_ID_IFF_BYTERUN1, "iff"},
>> >      { AV_CODEC_ID_MJPEG     , "jpeg"},
>> >      { AV_CODEC_ID_MJPEG     , "jpg"},
>> >      { AV_CODEC_ID_MJPEG     , "jps"},
>> > --
>> > 1.7.5.4
>> >
>>
>> First these two codecs should be merged into one;
>> second image demuxer should not use extensions to
>> detect files.
>
> +1, but that's a rather large task. Each still image codec would need a
> probe function. I toyed around with JPEG, PNG, GIF and BMP probes a
> while back, but I seem to have misplaced the code.
>
> In a more general sense, is changing codec of a stream ever allowed? I'm
> considering the hypothetical situation that someone mixes image types in
> a sequence.

It should be allowed and i see no problem with it.
Using only file extension to detect codec is fragile.