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• What codec should I use that is easy on the cpu to decode ?

  9 mars 2013, par James491

  I'm looking for a good match between file size and decoding time. I could care less about encoding. Ideally, is there a codec that takes a long time to encode but then is super easy to decode ? I'm currently working with raw video as that is the easiest I've found to decode in libavcodec but that is about 800MB for my 9 second video clip. Quality is very important. I'd prefer a lossless codec. Any suggestions ?

• Revision ef887974aa : vp8 fast quantizer with intrinsics Reduce dependency on offsets file by using i

  2 février 2013, par Johann

  Changed Paths : Modify /vp8/encoder/x86/quantize_sse2.asm Add /vp8/encoder/x86/quantize_sse2.c Modify /vp8/vp8cx.mk vp8 fast quantizer with intrinsics Reduce dependency on offsets file by using intrinsics. Disassembly shows improvements over previous assembly specifically in register management, (...)

• GStreamer with MPEG-TS Video4Linux ATSC/DVB Recording

  21 juin 2013, par Dustin Oprea

  I'm having an impossible time setting up a filtergraph to read from a recording that I made from my DVB video4linux device. Any help would be vastly appreciated.

  How I made the recording :

  To tune the channel :

  azap -c ~/channels.conf "Florida"

  To record the channel :

  cat /dev/dvb/adapter0/dvr0 > /tmp/test

  This is the way that recordings must be made (I can not use any GST DVB plugins to do this for me).

  I used tstools to identify that the recording is a TS stream :

  tstools/bin$ ./stream_type ~/recordings/20130129-202049
  
  Reading from /home/dustin/recordings/20130129-202049
  
  It appears to be Transport Stream

  ...but that there are no PAT/PMT frames :

  tstools/bin$ ./tsinfo ~/recordings/20130129-202049
  
  Reading from /home/dustin/recordings/20130129-202049
  
  Scanning 10000 TS packets
  
  
  
  Found 0 PAT packets and 0 PMT packets in 10000 TS packets

  I was able to produce a single ES (elementary stream) stream, by running ts2es :

  tstools/bin$ ./ts2es -pid 97 ~/recordings/20130129-202049 ~/recordings/20130129-202049.es
  
  Reading from /home/dustin/recordings/20130129-202049
  
  Writing to   /home/dustin/recordings/20130129-202049.es
  
  Extracting packets for PID 0061 (97)
  
  !!! 4 bytes ignored at end of file - not enough to make a TS packet
  
  Extracted 219258 of 248113 TS packets

  I am able to play the ES stream (even though the video is frozen on the first frame) :

  gst-launch-0.10 filesrc location=~/recordings/20130129-202049.es ! decodebin2 ! autovideosink
  
  gst-launch-0.10 filesrc location=~/recordings/20130129-202049.es ! decodebin2 ! xvimagesink
  
  gst-launch-0.10 playbin2 uri=file:///home/dustin/recordings/20130129-202049.es

  No matter what I do, though, I can't get the original TS file to open. However, it opens in Mplayer/FFMPEG, perfectly (but not VLC). This is the output of FFMPEG :

  ffmpeg -i 20130129-202049
  
  
  
  ffmpeg version 0.8.5-4:0.8.5-0ubuntu0.12.04.1, Copyright (c) 2000-2012 the Libav developers
  
    built on Jan 24 2013 18:03:14 with gcc 4.6.3
  
  *** THIS PROGRAM IS DEPRECATED ***
  
  This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
  
  [mpeg2video @ 0x9be7be0] mpeg_decode_postinit() failure
  
      Last message repeated 4 times
  
  [mpegts @ 0x9be3aa0] max_analyze_duration reached
  
  [mpegts @ 0x9be3aa0] PES packet size mismatch
  
  Input #0, mpegts, from '20130129-202049':
  
    Duration: 00:03:39.99, start: 9204.168844, bitrate: 1696 kb/s
  
      Stream #0.0[0x61]: Video: mpeg2video (Main), yuv420p, 528x480 [PAR 40:33 DAR 4:3], 15000 kb/s, 30.57 fps, 29.97 tbr, 90k tbn, 59.94 tbc
  
      Stream #0.1[0x64]: Audio: ac3, 48000 Hz, stereo, s16, 192 kb/s
  
  At least one output file must be specified

  This tells us that the video stream has PID 0x61 (97).

  I have been trying for a few days, so the following are only examples of a couple of attempts. I'll provide the playbin2 example first, since I know that thousands of people will respond, insisting that I just use that. It doesn't work.

  gst-launch-0.10 playbin2 uri=file:///home/dustin/recordings/20130129-202049
  
  
  
  Setting pipeline to PAUSED ...
  
  Pipeline is PREROLLING ...
  
  ERROR: from element /GstPlayBin2:playbin20/GstURIDecodeBin:uridecodebin0/GstDecodeBin2:decodebin20/GstMpegTSDemux:mpegtsdemux0: Could not determine type of stream.
  
  Additional debug info:
  
  gstmpegtsdemux.c(2931): gst_mpegts_demux_sink_event (): /GstPlayBin2:playbin20/GstURIDecodeBin:uridecodebin0/GstDecodeBin2:decodebin20/GstMpegTSDemux:mpegtsdemux0:
  
  No valid streams found at EOS
  
  ERROR: pipeline doesn't want to preroll.
  
  Setting pipeline to NULL ...
  
  Freeing pipeline ...

  It fails [probably] because no PID has been specified with which to find the video (the "EOS" error, I think).

  Naturally, I tried the following to start by demuxing the TS format. I believe it's the "es-pids" property that receives the PID in the absence of PMT information (which tstools said there weren't any, above), but I tried "program-number", too, just in case. gst-inspect indicates that one is hex and the other is decimal :

  gst-launch-0.10 -v filesrc location=20130129-202049 ! mpegtsdemux es-pids=0x61 ! fakesink
  
  gst-launch-0.10 -v filesrc location=20130129-202049 ! mpegtsdemux program-number=97 ! fakesink

  Output :

  gst-launch-0.10 filesrc location=20130129-202049 ! mpegtsdemux es-pids=0x61 ! fakesink
  
  Setting pipeline to PAUSED ...
  
  Pipeline is PREROLLING ...
  
  ERROR: from element /GstPipeline:pipeline0/GstMpegTSDemux:mpegtsdemux0: Could not determine type of stream.
  
  Additional debug info:
  
  gstmpegtsdemux.c(2931): gst_mpegts_demux_sink_event (): /GstPipeline:pipeline0/GstMpegTSDemux:mpegtsdemux0:
  
  No valid streams found at EOS
  
  ERROR: pipeline doesn't want to preroll.
  
  Setting pipeline to NULL ...
  
  Freeing pipeline ...
  
  dustin@dustinmicro:~/recordings$ gst-launch-0.10 -v filesrc location=20130129-202049 ! mpegtsdemux es-pids=0x61 ! fakesink
  
  Setting pipeline to PAUSED ...
  
  Pipeline is PREROLLING ...
  
  ERROR: from element /GstPipeline:pipeline0/GstMpegTSDemux:mpegtsdemux0: Could not determine type of stream.
  
  Additional debug info:
  
  gstmpegtsdemux.c(2931): gst_mpegts_demux_sink_event (): /GstPipeline:pipeline0/GstMpegTSDemux:mpegtsdemux0:
  
  No valid streams found at EOS
  
  ERROR: pipeline doesn't want to preroll.
  
  Setting pipeline to NULL ...
  
  Freeing pipeline ...
  
  dustin@dustinmicro:~/recordings$ gst-launch-0.10 -v filesrc location=20130129-202049 ! mpegtsdemux es-pids=0x61 ! fakesink
  
  Setting pipeline to PAUSED ...
  
  Pipeline is PREROLLING ...
  
  ERROR: from element /GstPipeline:pipeline0/GstMpegTSDemux:mpegtsdemux0: Could not determine type of stream.
  
  Additional debug info:
  
  gstmpegtsdemux.c(2931): gst_mpegts_demux_sink_event (): /GstPipeline:pipeline0/GstMpegTSDemux:mpegtsdemux0:
  
  No valid streams found at EOS
  
  ERROR: pipeline doesn't want to preroll.
  
  Setting pipeline to NULL ...
  
  Freeing pipeline ...

  However, when I try mpegpsdemux (for program streams (PS), as opposed to transport streams (TS)), I get further :

  gst-launch-0.10 filesrc location=20130129-202049 ! mpegpsdemux ! fakesink
  
  
  
  Setting pipeline to PAUSED ...
  
  Pipeline is PREROLLING ...
  
  
  
  (gst-launch-0.10:14805): GStreamer-CRITICAL **: gst_event_new_new_segment_full: assertion `position != -1' failed
  
  
  
  (gst-launch-0.10:14805): GStreamer-CRITICAL **: gst_mini_object_ref: assertion `mini_object != NULL' failed
  
  
  
  (gst-launch-0.10:14805): GStreamer-CRITICAL **: gst_pad_push_event: assertion `event != NULL' failed
  
  Pipeline is PREROLLED ...
  
  Setting pipeline to PLAYING ...
  
  New clock: GstSystemClock
  
  
  
  (gst-launch-0.10:14805): GStreamer-CRITICAL **: gst_event_new_new_segment_full: assertion `position != -1' failed
  
  
  
  (gst-launch-0.10:14805): GStreamer-CRITICAL **: gst_mini_object_ref: assertion `mini_object != NULL' failed
  
  
  
  (gst-launch-0.10:14805): GStreamer-CRITICAL **: gst_pad_push_event: assertion `event != NULL' failed
  
  
  
  (gst-launch-0.10:14805): GStreamer-CRITICAL **: gst_event_new_new_segment_full: assertion `position != -1' failed
  
  
  
  (gst-launch-0.10:14805): GStreamer-CRITICAL **: gst_mini_object_ref: assertion `mini_object != NULL' failed
  
  
  
  (gst-launch-0.10:14805): GStreamer-CRITICAL **: gst_pad_push_event: assertion `event != NULL' failed
  
  
  
  (gst-launch-0.10:14805): GStreamer-CRITICAL **: gst_event_new_new_segment_full: assertion `position != -1' failed
  
  
  
  (gst-launch-0.10:14805): GStreamer-CRITICAL **: gst_mini_object_ref: assertion `mini_object != NULL' failed
  
  
  
  (gst-launch-0.10:14805): GStreamer-CRITICAL **: gst_pad_push_event: assertion `event != NULL' failed
  
  
  
  
  
  ...
  
  
  
  
  
  Got EOS from element "pipeline0".
  
  Execution ended after 1654760008 ns.
  
  Setting pipeline to PAUSED ...
  
  Setting pipeline to READY ...
  
  Setting pipeline to NULL ...
  
  Freeing pipeline ...

  I'll still get the same problem whenever I use the mpegtsdemux, even if it follows mpegpsdemux, above.

  I don't understand this, since I haven't even picked a PID yet.

  What am I doing wrong ?

  Dustin