hi, Michael Smith schrieb: > 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 > Nokia will contribute a aacparser based on baseparse real soon. Stefan
