chromecast: transcode audio to MP3 320 kbps instead of 96 kbps

Chromecast transcoding code uses either Vorbis or MP3 for audio.  For Vorbis,
quality=4 is used, but for MP3 no bitrate or quality setting is set, which
leads to default 96 kbps poor quality audio.

This patch explicitly sets 320 kbps bitrate for MP3, for much better audio
quality.

Tested on Chromecast 3.

Signed-off-by: Thomas Guillem <[email protected]>

Author: ValdikSS

modules/stream_out/chromecast/cast.cpp

@@ -924,6 +924,8 @@ sout_stream_sys_t::GetAcodecOption( sout_stream_t *p_stream, vlc_fourcc_t *p_cod
      * devices (Chromecast 1 & 2) */
     if( *p_codec_audio == VLC_CODEC_VORBIS )
         ssout << "aenc=vorbis{quality=4},";
+    else if( *p_codec_audio == VLC_CODEC_MP3 )
+        ssout << "ab=320,";
     return ssout.str();
 }