From: gulshan k. <gul...@gm...> - 2008-08-07 03:12:02
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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 |
From: Stefan K. <en...@ho...> - 2008-08-07 07:54:40
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hi, there parser uses GST_READ_* macros and they are not alignment save. There is some discussion ongoing to make the alignment save to ease portability. http://bugzilla.gnome.org/show_bug.cgi?id=545714 Stefan gulshan karmani schrieb: > 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 > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's challenge > Build the coolest Linux based applications with Moblin SDK & win great prizes > Grand prize is a trip for two to an Open Source event anywhere in the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > Gstreamer-openmax mailing list > Gst...@li... > https://lists.sourceforge.net/lists/listinfo/gstreamer-openmax > |
From: Tim M. <tim...@co...> - 2008-08-20 22:07:12
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On Thu, 2008-08-07 at 10:55 +0300, Stefan Kost wrote: > there parser uses GST_READ_* macros and they are not alignment save. > There is some discussion ongoing to make the alignment save to ease > portability. > http://bugzilla.gnome.org/show_bug.cgi?id=545714 That's not what that bug is about. Those macros should be safe already in terms of alignment (provided the configure check in core worked correctly). My guess is that the problem is in libgstriff in -base, which doesn't use those macros everywhere to read riff-related structures. The same might also be true for avidemux, I haven't checked. Cheers -Tim |
From: Felipe C. <fel...@gm...> - 2008-12-11 20:12:54
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On Thu, Aug 7, 2008 at 5:12 AM, gulshan karmani <gul...@gm...> 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. > > [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" Sorry for the late reply. Normally GStreamer requires timestamps, and probably the alsasink is expecting them. You can try with omx_aacdec use-timestamps=false, but it would be better if you add an AAC parser before the decoder. -- Felipe Contreras |