[FFmpeg-devel] Help with adding new adpcm decoder

Moritz Barsnick barsnick at gmx.net
Tue Nov 22 16:24:12 EET 2016


On Tue, Nov 22, 2016 at 15:04:46 +0100, Michael Niedermayer wrote:
> On Tue, Nov 22, 2016 at 12:47:04PM +0100, James Darnley wrote:
> > The file starts with a riff wave header that lies about being pcm and
> > other values, but I can force the decoder with ffmpeg.  In the data
> > block (which has an incorrect size) the data is divided into frames and
> > subframes of constant size (except for the last one).
[...]
> but maybe writing a new demuxer is cleaner, wav is not a format
> with packets that contain size values like the 8 byte headers

PCM being encapsulated in packets with "proprietary" header values to
me also sounds like the task for a demuxer. The "codec" underneath,
once the overhead is stripped, looks like plain PCM again, right?

> the 3rd option is a AVParser to take the output from the wav
> demuxer and turn it into properly packetized data

Would that be like an input-bitstream filter?

Moritz


More information about the ffmpeg-devel mailing list