On Wed, Aug 6, 2008 at 8:08 PM, gulshan karmani <gulshan.karmani at gmail.com> wrote: > 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. I assume this is something doing unaligned multibyte reads? It's quite possible that this is something in avidemux - not exactly a bug, but code that could be improved. If you can fix it, we'd certainly include your patches in future versions. > > [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. Do not use that. mp3parse is the appropriate element for parsing mp3 bitstreams. It should get autoplugged. > > 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 ? No. Currently, I don't think there's a raw AAC bitstream parser in gstreamer. If you could contribute one, that would be very welcome - quite a few people have asked for it. Basing this on mp3parse might be a good idea - there's probably lots of things that would be similar. Mike
