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fixing audio
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Kru
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Recently, I'm trying to stream a remote desktop using ffmpeg. The goal is to being able to send what is shown on one of the computer's screen to another computer while being able to choose settings like the output resolution, etc.

It is a small nearly working proof of concept. When done, I'll be able to replace VNC by using ffmpeg streaming with x2x or synergy for forwarding keyboard and mouse events.

Now, I can start streaming using:

ffmpeg -f x11grab -s "1600x1200" -i ":0" \
    -f alsa -i pulse \
    -s 800x600 -b 800k200k -f avimpegts - \
    | mplayer -cache 1024 -
#
# I have pulse audio configured so that `-i pulse` will
# The output can sent through for example netcat to another host
#

The latency depends on the encoding options. With these options, the delay between the screen update and the video update is arround 800ms.

Thing I'm trying to achieve:

  • Reach a latency of 100ms.

    Reach a latency of 100ms.

  • When mplayer is executed it complains that it cannot seek in lear streams and there is no audio. I still have the sound when I'm saving the output to a file and play it.

    When mplayer is executed it complains that it cannot seek in lear streams and there is no audio. I still have the sound when I'm saving the output to a file and play it.

    EDIT: After adding -cache, messages to seek in linear streams no longer appear. Changing output format to -f mpegts makes the audio work.

  • It would be great if the encoding wouldn't take 100% of one of the cpu cores (secondary goal).

    It would be great if the encoding wouldn't take 100% of one of the cpu cores (secondary goal).

After some reseach on the internet, I think that these problems are related to the codecs/options I should use. Yet I don't know the differences between the existing possibilities. Could you give me some options that would solve my problems? Also, is VLC a good alternative and if so what would be the equivalent commands to stream from one desktop to another?

Recently, I'm trying to stream a remote desktop using ffmpeg. The goal is to being able to send what is shown on one of the computer's screen to another computer while being able to choose settings like the output resolution, etc.

It is a small nearly working proof of concept. When done, I'll be able to replace VNC by using ffmpeg streaming with x2x or synergy for forwarding keyboard and mouse events.

Now, I can start streaming using:

ffmpeg -f x11grab -s "1600x1200" -i ":0" \
    -f alsa -i pulse \
    -s 800x600 -b 800k -f avi - \
    | mplayer -
#
# I have pulse audio configured so that `-i pulse` will
# The output can sent through for example netcat to another host
#

The latency depends on the encoding options. With these options, the delay between the screen update and the video update is arround 800ms.

Thing I'm trying to achieve:

  • Reach a latency of 100ms.
  • When mplayer is executed it complains that it cannot seek in lear streams and there is no audio. I still have the sound when I'm saving the output to a file and play it.
  • It would be great if the encoding wouldn't take 100% of one of the cpu cores (secondary goal).

After some reseach on the internet, I think that these problems are related to the codecs/options I should use. Yet I don't know the differences between the existing possibilities. Could you give me some options that would solve my problems? Also, is VLC a good alternative and if so what would be the equivalent commands to stream from one desktop to another?

Recently, I'm trying to stream a remote desktop using ffmpeg. The goal is to being able to send what is shown on one of the computer's screen to another computer while being able to choose settings like the output resolution, etc.

It is a small nearly working proof of concept. When done, I'll be able to replace VNC by using ffmpeg streaming with x2x or synergy for forwarding keyboard and mouse events.

Now, I can start streaming using:

ffmpeg -f x11grab -s "1600x1200" -i ":0" \
    -f alsa -i pulse \
    -s 800x600 -b 200k -f mpegts - \
    | mplayer -cache 1024 -
#
# I have pulse audio configured so that `-i pulse` will
# The output can sent through for example netcat to another host
#

The latency depends on the encoding options. With these options, the delay between the screen update and the video update is arround 800ms.

Thing I'm trying to achieve:

  • Reach a latency of 100ms.

  • When mplayer is executed it complains that it cannot seek in lear streams and there is no audio. I still have the sound when I'm saving the output to a file and play it.

    EDIT: After adding -cache, messages to seek in linear streams no longer appear. Changing output format to -f mpegts makes the audio work.

  • It would be great if the encoding wouldn't take 100% of one of the cpu cores (secondary goal).

After some reseach on the internet, I think that these problems are related to the codecs/options I should use. Yet I don't know the differences between the existing possibilities. Could you give me some options that would solve my problems? Also, is VLC a good alternative and if so what would be the equivalent commands to stream from one desktop to another?

Source Link
Kru
  • 188
  • 1
  • 1
  • 8

Low-latency streaming using ffmpeg

Recently, I'm trying to stream a remote desktop using ffmpeg. The goal is to being able to send what is shown on one of the computer's screen to another computer while being able to choose settings like the output resolution, etc.

It is a small nearly working proof of concept. When done, I'll be able to replace VNC by using ffmpeg streaming with x2x or synergy for forwarding keyboard and mouse events.

Now, I can start streaming using:

ffmpeg -f x11grab -s "1600x1200" -i ":0" \
    -f alsa -i pulse \
    -s 800x600 -b 800k -f avi - \
    | mplayer -
#
# I have pulse audio configured so that `-i pulse` will
# The output can sent through for example netcat to another host
#

The latency depends on the encoding options. With these options, the delay between the screen update and the video update is arround 800ms.

Thing I'm trying to achieve:

  • Reach a latency of 100ms.
  • When mplayer is executed it complains that it cannot seek in lear streams and there is no audio. I still have the sound when I'm saving the output to a file and play it.
  • It would be great if the encoding wouldn't take 100% of one of the cpu cores (secondary goal).

After some reseach on the internet, I think that these problems are related to the codecs/options I should use. Yet I don't know the differences between the existing possibilities. Could you give me some options that would solve my problems? Also, is VLC a good alternative and if so what would be the equivalent commands to stream from one desktop to another?