[Ffmpeg-devel] Interlaced decoding internals?
Tue Feb 6 13:31:04 CET 2007
Michael Niedermayer wrote:
> On Tue, Feb 06, 2007 at 11:08:20AM +0100, Baptiste Coudurier wrote:
>> Michael Niedermayer wrote:
>>> On Mon, Feb 05, 2007 at 08:31:41PM +0200, Kostya wrote:
>>>> I'm working on adding interlaced frame support for VC-1 and
>>>> has some question regarding AVCodecContext internals:
>>>> What do avctx->interlaced_frame, avctx->top_field_first
>>>> and avctx->repeat_pict affect if set by decoder?
>>> they are not in AVCodecContext but AVFrame
>>> they affect display, top_field_first affects the order in which
>>> fields are shown, interlaced_frame affects if the frame is shown
>>> as frame or as 2 fields at 2 seperate times (assuming the player
>>> applictaion cares about the at all of course ...)
>> You'll laugh, what can I do if the interlaced info is in the container ?
>> I have some mjpeg a bottom field first, and info is in "fiel" atom.
>> I'll fix decoder, but I need a way to supply that info.
>> What do you prefer ? Adding a field to avctx ?
> avctx is problematic as top-field-first can change between frames in
> MPEG so with decoder delay and multiple threads its the perfect recipe
> for troubble
> adding top-field-first to AVStream seems like the better solution,
> that way the demuxer can export it without interfering with the codec
> the same may (or may not ...) be a good idea for width/height, so
> the width and height for mpeg4/h263 in mov could be dealt with nicer
> maybe ...
So, then I need to set picture->top_field_first before passing it to the
Attached patch is working, but IMHO is ugly.
Baptiste COUDURIER GnuPG Key Id: 0x5C1ABAAA
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