AUDIO support
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Veejay has limited audio support.


PREPARE
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You need an AVI file with an audio track encoded in signed PCM WAVE, 44-48Khz, 2 channels (stereo) (16 bit)

For example with ffmpeg/avconv you can use the "PCM signed 16-bit little-endian" codec named "pcm_s16le"

# avconv myvideo.mp4 -q:v 1 -vcodec mjpeg -acodec pcm_s16le -s 1024x576 myvideo.avi


RUN
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Veejay only has support for jackd1 (the old jack)

Start jackd prior to starting veejay :

# jackd -d alsa -P

Note : jack audio server must be configured with the same sampling rate as the loaded video file.

Now, start veejay:

# veejay -m80 /path/to/mjpeg.avi

Use the -m commandline option to allow veejay to cache video frames when sampling. This will reduce disk latency,
allowing for smoother audio playback (especially when used in combination of speed/pitch changes) 

The -m commandline option is further explained in docs/HowtoCache.txt

Nota : The video you start veejay with must contains a sound stream, else the jack transport is not started ... even if -a option

AUDIO PLAYBACK PROBLEMS
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Q: What can I do about the warning "Rendering audio/video frame takes too long (measured 44 ms). Can't keep pace with audio!" 


A(1): You can start veejay with the -m commandline option. The warnings are less frequent or dissapear when the whole sample is cached in memory.

A(2): You can disable veejay's multithreaded pixel operations:
  
# export VEEJAY_MULTITHREAD_TASKS=0
# veejay -m80 /path/to/mjpeg.avi

A(3): Have a dedicated veejay-server machine and connect with reloaded through the network

A(4): Run with a different video codec or lower the video resolution



KEYS
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      [ a,s,d,f,g,h,j,k,l ] : Increase speed 1x,2x,3x,...

ALT + [ a,s,d,f,g,h,j,k,l ] : Decrease speed (1/2,1/4, ...)

KP 6 / ->                   : Play forward

KP 4 / <-                   : Play backward