Decodebin:跳过一条流

Question

我想在树莓派上用Gstreamer对我的电视录像进行编码。受this post启发，以下代码适用于下载的mkv：

/usr/bin/gst-launch-1.0 -e filesrc location=/media/Seagate/complete/TV/Better\ Call\ Saul/Season\ 01/Better\ Call\ Saul\ -\ S01E10\ -\ Marco.mkv ! decodebin name=demux ! queue ! audioconvert ! audio/x-raw ! audiorate ! avenc_ac3 bitrate=320000 ! mux. mpegtsmux name=mux ! filesink location=/media/Seagate/pvr/Buitenhof_compressed.mkv demux. ! queue ! videoconvert ! deinterlace ! omxh264enc target-bitrate=2000000 control-rate=1 inline-header=true periodicty-idr=250 interval-intraframes=250 ! "video/x-h264,profile=high" ! h264parse ! mux.

使用的文件具有以下结构(gst-discoverer输出)：

Topology:
  container: Matroska
    audio: AC-3 (ATSC A/52)
    video: H.264

Properties:
  Duration: 0:49:18.048000000
  Seekable: yes
  Tags: 
      container format: Matroska
      audio codec: AC-3 audio
      language code: und
      video codec: H264
      minimum bitrate: 7288
      bitrate: 24263
      maximum bitrate: 9206

但是，我的录制软件(TVHeadend)会输出以下格式：

Topology:
container: Matroska
    subtitles: application/x-subtitle-unknown
    subtitles: application/x-subtitle-unknown
    audio: MPEG-1 Layer 2 (MP2)
    audio: AC-3 (ATSC A/52)
    audio: MPEG-1 Layer 2 (MP2)
    video: H.264

Properties:
  Duration: 0:00:06.440000000
  Seekable: yes
  Tags: 
      title: Buitenhof
      extended comment: DATE_BROADCASTED=2015-05-24 10:05:00
      container format: Matroska
      audio codec: MPEG 1 Audio, Layer 2
      language code: nl
      nominal bitrate: 256000
      has crc: true
      channel mode: stereo
      video codec: H264
      minimum bitrate: 8972400
      bitrate: 16546750
      maximum bitrate: 22841600

我如何告诉管道跳过字幕流而使用AC-3和H264流？我已经尝试了decodebin name=demux demux.audio_01，但没有效果。输出为

Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
Missing element: application/x-subtitle-unknown decoder
Missing element: application/x-subtitle-unknown decoder

如果能有字幕也不错，但没有字幕我也能活下去。

Answer 1

流的顺序与问题无关。可用视频内存不足。对于全高清mkv，我需要将显存分割设置为128MB。

一种方法是在高级菜单下为我的raspbian版本运行sudo raspi-config，视频内存拆分。需要重新启动。

在此之后，我发布的命令就可以工作了