[FFmpeg-devel] ARMovie/RPL demuxer

Eli Friedman eli.friedman
Mon Mar 24 03:35:28 CET 2008

On Sun, Mar 23, 2008 at 4:02 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
>  floats are not accurate things, this makes regression tests hard.
>  The string should be parsed into a AVRational with no intermediate
>  float/double.

Is there some existing method to parse stuff like 25.000 directly into
an AVRational?  I can't seem to find one.  (I can put something
together if there isn't, though.)

>  > +        // There should always be frames_per_chunk frames in a chunk.
>  > +        // (This should be checked once video decoding is implemented.)
>  > +        pkt->duration = rpl->frames_per_chunk;
>  1 AVPacket == 1 frame. Either demuxer or parser has to split them if there
>  are more.

Mmm.  The only known Escape 122 sample happens to have one frame per
chunk, so it's not an issue there.

For Escape 124, this gets to be a bit tricky because the demuxer has
to actually read first 8 bytes of the frame to figure out its size,
and this includes some flags that the decoder needs.  I guess in that
case, I can seek backwards and afterwards so that data ends up in the
packet.  Or is there some other preferred way to do this?

For Escape 130, it looks like the demuxer can just consume the length
of the frame.

-Eli Friedman

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