The VideoLAN Forums

Hello, I have a Matroska file with 2 audio streams. The first is AC3/Dolby digital 5.1 in a foreing language, the second is in local language and has the problem.

VLC sees the stream as DTS Stereo (2 channels), with a bitrate of 768kbit/s. When I play it with VLC integrated software decoding and downmixing (laptop sound card, stereo headphones, etc) it plays just static noise, but if I play it on my old Creative Labs loudspeaker with hardware DTS decoder over SPDIF, it plays perfectly and the sound comes out from all 6 speakers. I guess the stream is really a 6 channels in 5.1 surround configuration: 768kbit/s is too much for stereo encoding.

I then suppose that the file il wrongly encoded or at least it has the wrong header, and now i'm here asking for help: is it possible to edit the big MKV file manually or with a software for changing the speaker configuration without re-encode all the video? Or is it possible for VLC developers to detect the wrong channels number in the header and play the stream correctly like hardware decoder does?

any help would be really appreciated

Thanks
Jack

Please open Tools -> Messages (set Verbosity to 2) before you start the playback, and then paste the full resulting log here or on Pastebin.com if it's too long.

Also upload a short sample of a problematic file to either http://streams.videolan.org/upload/ or to Zippyshare.com (200 MB max) or to EmbedUpload.com, the latter will upload the file for you to several other hosts (use the default ones) and then post the link to the file here.

If needed cut it with DGsplit and read here about how to do it:
viewtopic.php?f=14&t=57724&p=193335#p193335
50 MB max should be enough.

Hello, thanks for your reply.

This is the (almost) full log: i've just removed duplicate messages.
The error i receive after switching to the damaged audio stream is this:
dtstofloat32 warning: dca_block failed for block 0

EDIT: Upladed a 20mb chunk of video. I was able to reproduce the issue playing it.

Thanks

Thank you, i'll follow the ticket there!