[Gstreamer-openmax] Gstreamer Openmax plugins and Media demuxers

[gulshan karmani]

Hi All,

      I have some questions regarding Gstreamer Based Demuxers used
inside poky for media playback,

1. While using  'avidemux'  as a demuxer plugin we get continuous
'Alignment Traps'
which is affecting the audio quality. We have a cmdline option to tell
the kernel to fix these traps and suppress the warning but this could
be just a workaround.

Is this alignment trap caused by demuxer ? Or we need to take care of something
in lower layers ?
Instead of avidemux if we use 'ffdemux_avi' we do not get these traps.

[We use Gst-omx decoders below which are calling ffmpeg for decoding,
ffmpeg has been hardware accelerated].

2. Which are the Stand-alone Aac and mp3 demuxers inside Gstreamer to be used ?

We are trying to use ffdemux_mp3 for mp3 and getting some package
building issues.

While for Aac we tried gst faad but this is being identified as Aac
decoder along with parser. Could we not use this plugin just as a
demuxer ?

Following chains are working for AAC :
"gst-launch filesrc
location=/media/sdmmc0p1/streams/bass47_1_ADTS_LTP.aac ! faad !
alsasink"

"gst-launch omx_filereadersrc
file-name=/media/sdmmc0p1/streams/AAC_TestStreams/al09_44.aac !
omx_aacdec ! omx_audiosink"

While the ones which we want to use and not working are :
"gst-launch filesrc
location=/media/sdmmc0p1/streams/bass47_1_ADTS_LTP.aac ! omx_aacdec !
alsasink"

"gst-launch omx_filereadersrc
file-name=/media/sdmmc0p1/streams/AAC_TestStreams/al09_44.aac !
omx_aacdec ! alsasink"


Thanks for any quick suggestions in this regard.

Best Regards,

Gulshan Karmani