Re: [fuse-emulator-devel] [fuse-emulator-cvs] SF.net SVN: fuse-emulator:[4888] trunk/fuse-utils

[Sergio B. <ser...@gm...>]

On 16/02/13 04:40, fr...@us... wrote:
> Revision: 4888
>            http://sourceforge.net/p/fuse-emulator/code/4888
> Author:   fredm
> Date:     2013-02-16 03:40:21 +0000 (Sat, 16 Feb 2013)
> Log Message:
> -----------
> Check the codec supports signed 16 bit PCM samples before trying to use them.
>

Hi Fred,

I think this check is not working right at all, e.g.,

1. avcodec_find_encoder_by_name() in out_write_ffmpegheader() looks for 
a encoder, let's name it CODEC1.
2. check_sample_fmt() check the input format of CODEC1.
3. avcodec_find_encoder() in open_audio() looks for the *first* 
non-experimental encoder of the same type, or an experimental encoder if 
not available. Let's name it CODEC2.
4. fmfconv use CODEC2 for transcoding.

So check_sample_fmt() could test the properties of a codec that is not 
used in the final encoding.

Another problem is the non deterministic behaviour of --acodec switch, 
e.g., a user request the `aac' encoder but fmfconv ends using 
`libvo_aacenc' in a hidden way.

I propose these fixes:
- look for an encoder in out_write_ffmpegheader() and use the same 
encoder on later stages.
- remove ffmpeg_acodec and ffmpeg_vcodec from the ipod profile, so 
av_guess_format() could suggest an encoder better than ffmpeg's `aac' 
(libvo_aacenc on windows).

http://pastebin.com/K3MffVAS

Cheers,
Sergio