Lukas Eklund
Level 1 (0 points)

Q: copy and transcode response fails: "Found unknown audio codec in source "

I have a watcher that triggers a copy response that transcode's to ProRes 422 and creates an asset in FCS. It works very well most of the time except when it fails with this error: "Found unknown audio codec in source."

The source it fails on is MPEG-2 and the audio track is mp2 16-bit/48KHz stereo. Which is exactly the same as other clips that work just fine. Compressor handles the source clips just fine and I can't see any difference between the audio tracks using VideoSpec.

Final Cut Server is version 1.5.2 and Compressor is 3.5.3 running on OS X Server 10.5.8.

Here is partial audio output from VideoSpec for the source clip that fails:

Audio Track(s) Parameters
- Format: Mpeg-1 layer 2 (mp2)
- Size: 700 KiB (6%)
- FourCC: 0x50
- Number(s) and language(s): 192 (0xC0): Undefined
- Details: -
- Profile: Layer 2
- Bitrate: 256 Kbps
- Bitrate mode: Constant
- Resolution: 16 bits
- Rate: 48.0 KHz
- Channel(s): 2 (stereo)
- Position: Undefined
- Encoding Library: Undefined
- Additional Parameters: Not available

A search of the forum doesn't turn up any results, but I figured I would ask in hopes that someone else has experienced this issue. Any help is greatly appreciated.

Lukas

XServe, Mac OS X (10.5.8)

Posted on Mar 28, 2011 1:09 PM

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Lukas Eklund

Q: copy and transcode response fails: "Found unknown audio codec in source "

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  • Helpful answers

  • by BenB,

    BenB BenB Apr 2, 2011 6:38 AM in response to Lukas Eklund
    Level 6 (10,031 points)
    Audio
    Apr 2, 2011 6:38 AM in response to Lukas Eklund
    MPEG-2? Where is this source coming from? It must have gone through an odd Mux-ing process that's not supported by Compressor. Where did the source video clip come from? It may need to be converted into something QT compatible first.

  • by Lukas Eklund,

    Lukas Eklund Lukas Eklund Apr 11, 2011 1:42 PM in response to BenB
    Level 1 (0 points)
    Apr 11, 2011 1:42 PM in response to BenB
    The source clips are being generated by ffmpeg and are either x264 from a video archive or mpeg-2 from a snapstream server. I've tracked down the issue to mpeg-2 video from the snapstream servers. The clips generated by snapstream are not always readable for some reason. I added a simple check and to retranscode to valid mpeg-2 before the ingest and that fixed the thumbnail problem. The weird part is that compressor was able to transcode the problem videos to prores422 just fine. It was only the thumbnail generation that was an issue.