Bug 146307 – media-video/transcode-1.0.2-r2 export to dvraw messes up audio

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Craig Lawson 2006-09-04 13:19:51 UTC]

I submitted this to transcode-devel. Didn't get a reply, and I don't want it to get lost.


When exporting to rawdv format, encoder->samples_this_frame was set to the number of audio bytes in the frame, not the number of samples. This causes audio samples to be either dropped or added, and when samples are added, they contain stack junk.

Example: the DV format encodes the number of audio samples as (nSamples - 1580) & 0x3F. At 48KHz NTSC, a typical frame contains 1602 samples, and is encoded as 22. Transcode was incorrectly specifying 1602 * 4 = 6408 samples, which is encoded as 28 -- adding 6 extra samples!
  The solution is to divide by 2 * size(int16_t) = 4 (because transcode always passes 2 channels to dv_encode_full_audio).

Example command:
  transcode -i movie.avi -y dvraw -uyvy -o movie.dv

[Comment 1 Craig Lawson 2006-09-04 13:21:03 UTC]

Created attachment 96005 [details, diff]
transcode 1.0.2 patch to fix dvraw audio export

[Comment 2 Diego Elio Pettenò (RETIRED) 2006-10-02 00:40:39 UTC]

Can you please submit this as an unified diff?

[Comment 3 Craig Lawson 2006-10-04 22:31:15 UTC]

Created attachment 98812 [details, diff]
transcode 1.0.2 patch to fix dvraw audio export (unified diff)

Patch resubmitted in unified diff format.

[Comment 4 Steve Dibb (RETIRED) 2007-02-01 03:38:44 UTC]

Fixed in -r4 in CVS, thanks Craig