Ffmpeg 带有MPEG-TS Video4Linux ATSC/DVB录制的GStreamer

我无法设置一个filtergraph来读取我用DVB video4linux设备录制的录音。任何帮助都将不胜感激

我是如何录制的：

要调整频道，请执行以下操作：

azap -c ~/channels.conf "Florida"

要录制频道，请执行以下操作：

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

这是必须录音的方式（我不能使用任何GST DVB插件为我做这件事）

我使用tstools来确定录制是TS流：

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

…但不存在PAT/PMT框架：

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

通过运行ts2es，我能够生成单个ES（基本流）流：

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

我能够播放ES流（即使视频在第一帧冻结）：

但是，无论我做什么，我都无法打开原始TS文件。但是，它在Mplayer/FFMPEG中完全打开（但不是VLC）。这是FFMPEG的输出：

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

这告诉我们视频流具有PID 0x61（97）

我已经尝试了几天，所以下面只是几个尝试的例子。我将首先提供playbin2示例，因为我知道成千上万的人会响应，坚持我只是使用它。它不起作用

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 ...

它失败[可能]是因为没有指定用于查找视频的PID（我认为是“EOS”错误）

当然，我尝试了以下方法，首先对TS格式进行解组。我相信是“es pids”属性在没有PMT信息的情况下接收PID（tstools说上面没有），但我也尝试了“程序号”，以防万一。gst inspect表示一个为十六进制，另一个为十进制：

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

输出：

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 ...

但是，当我尝试mpegpsdemux（针对程序流（PS），而不是传输流（TS））时，我得到了进一步的结果：

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 ...

无论何时使用mpegtsdemux，我仍然会遇到同样的问题，即使它遵循上面的mpegpsdemux

我不明白这一点，因为我甚至还没有选择PID

我做错了什么

达斯汀

答对了

事实证明，这个问题主要是由MPEG-TS广播流中典型的无效帧引起的。playbin2首先通过mencoder运行TS文件来重建它（无需重新编码），它突然工作了：

mencoder 20130129-202049 -oac copy -ovc copy -o 20130129-202049.copy

正如mpegtsdemux的作者告诉我的，flutsdemux是较新的，应该优先于较旧的mpegtsdemux。flutsdemux还可以更好地处理这些格式错误的帧

编辑

不幸的是，这是错误的。mencoder虽然被指示复制流，但将其重新打包为AVI，而不是保留为MPEGT：

$ gst-discoverer-1.0 ~/capture_0051_WXEL.dvb.distill
Analyzing file:///home/dustin/capture_0051_WXEL.dvb.distill
Done discovering file:///home/dustin/capture_0051_WXEL.dvb.distill

Topology:
  container: Audio Video Interleave (AVI)
    audio: AC-3 (ATSC A/52)
    video: MPEG-2 Video

Properties:
  Duration: 0:00:12.696016666
  Seekable: yes
  Tags: 
      encoder: MEncoder svn r34540 (Ubuntu), built with gcc-4.7
      container format: AVI
      audio codec: AC-3 audio
      bitrate: 384000
      video codec: MPEG 2 Video

这就是说，当我在非广播状态下录制时，PMT数据包似乎不存在。mplayer/mencoder似乎可以解决这个问题，而GStreamer和VLC则会阻塞数据。当我使用相同的设备记录ATSC/NTSC电缆馈送时，PMT数据包如预期的那样出现了。您可以使用“tstools”包中的“tsreport”确定是否存在某些数据包类型：

OTA提要：

$ tsreport -v capture_20130621-0402.trunc | grep PMT
!!! 60 bytes ignored at end of file - not enough to make a TS packet

电缆馈线：

$ tsreport -v capture_20130621-1118.ntsc.qam256.Florida.dvb | grep PMT
   31960: TS Packet 171 PID 0230 [pusi] PMT
   73508: TS Packet 392 PID 0230 [pusi] PMT
  101520: TS Packet 541 PID 0230 [pusi] PMT
  164688: TS Packet 877 PID 0230 [pusi] PMT

---

希望这能节省一些时间。我花了足够多的时间。

事实证明，zap有一个参数“-p”，它将导致PMT数据包不被过滤（或者，更确切地说，允许那些PID）。因此，MPEGTS将完全正确且结构良好。我使用的是“azap”，与它的三个兄弟不同，它的“-h”帮助非常差。另外，手册页中没有标识“-p”参数（至少在我的版本中没有）。

$ tsreport -v capture_20130621-1118.ntsc.qam256.Florida.dvb | grep PMT
   31960: TS Packet 171 PID 0230 [pusi] PMT
   73508: TS Packet 392 PID 0230 [pusi] PMT
  101520: TS Packet 541 PID 0230 [pusi] PMT
  164688: TS Packet 877 PID 0230 [pusi] PMT