[Ffmpeg-devel] [PATCH]add codec id for TTA and WavPack in riff.c

[David Bryant]

Hi,

yong wrote:
> Hi, with this pacth applied,
> trasncoding tta/wavpack to other audio codec in ffmpeg  will work,
> playback in ffplay will work too. :)
>
> Index: libavformat/riff.c
> ===================================================================
> --- libavformat/riff.c	(revision 6533)
> +++ libavformat/riff.c	(working copy)
> @@ -191,6 +192,8 @@
>      { CODEC_ID_ADPCM_CT, 0x200 },
>      { CODEC_ID_ADPCM_SWF, ('S'<<8)+'F' },
>      { CODEC_ID_TRUESPEECH, 0x22 },
> +    { CODEC_ID_TTA, MKTAG('T', 'T', 'A', '1') },
> +    { CODEC_ID_WAVPACK, MKTAG('W', 'V', 'P', 'K') },
>  
>      // for NuppelVideo (nuv.c)
>      { CODEC_ID_PCM_S16LE, MKTAG('R', 'A', 'W', 'A') },
>
>
>   
I am the developer of WavPack, but I'm very new to ffmpeg and I don't 
really understand what this does. It is in a list of format ids for the 
wav container but WavPack in wav is not supported. Also, in the wav 
header those ids are only 16-bit so WVPK can't fit. I assume that this 
table means something else in the ffmpeg context, but I could not figure 
out what (especially since I did not see FLAC in there and I know that's 
supported).

I haven't made it through all the docs yet (or built the code) but any 
light shed on this would be appreciated. As was mentioned, the signature 
for WavPack blocks is "wvpk", so that would be a fine choice by me for 
this (assuming it's not really a wav format_id).

I also very much appreciate the work done to add WavPack support to 
ffmpeg. Once I get a feel for everything (and get version 4.4 released) 
I may be able to contribute to WavPack support also.

Thanks,
David