Ticket #9 (closed defect: fixed)

Opened 2 years ago

Last modified 4 months ago

No sound output with 1.7

Reported by: dscottbuch@mac.com Assigned to: gbooker
Priority: normal Milestone:
Component: a52codec Version:
Severity: normal Keywords: no sound output
Cc:

Description

I have a number of avi's that I've created with ffmpegx. They are all video compressed with the mencoder mpeg4 codec and the audio is 'passedthrough' as AC3. I'm running on a macbook pro system. I've downloaded the 1.7 source code and made the project with Xcode 2.4. The problem I'm having is that some of the files play with sound and some don't, there is just silence.

Change History

(follow-up: ↓ 2 ) 09/17/06 12:27:25 changed by gbooker

  • status changed from new to assigned.

Not sure if you ran into this or not, but 1.7 had issues playing back mono audio. I fixed this in version 1.7.1.

If that doesn't resolve your issue, could you attach a small sample which exhibits this behavior (hopefully one that is copyright free)? Then I can start to track down what the issue is.

(in reply to: ↑ 1 ) 09/17/06 17:54:50 changed by anonymous

Replying to gbooker:

Not sure if you ran into this or not, but 1.7 had issues playing back mono audio. I fixed this in version 1.7.1. If that doesn't resolve your issue, could you attach a small sample which exhibits this behavior (hopefully one that is copyright free)? Then I can start to track down what the issue is.

Thanks. I did download the latest source and rebuild 1.7.1 and didn't help. There is a piece of an avi example - MarchOfThePenguins?_piece.avi - on my idisk (user = dscottbuch) public folder. This is part of a DVD i own so falls under fair-use. Hope this helps track down the problem (I couldn't attached anything as the upload limit is set to 262kB.

Thanks,

(follow-up: ↓ 4 ) 09/19/06 10:01:12 changed by dscottbuch@mac.com

Finally thought to look at the console during the failure and found

No accelerated IMDCT transform found

which I traced to the imdct.c routine and the define

LIBA52_DJBFFT

Hope this helps

(in reply to: ↑ 3 ) 09/19/06 15:19:35 changed by anonymous

Replying to dscottbuch@mac.com:

Finally thought to look at the console during the failure and found No accelerated IMDCT transform found which I traced to the imdct.c routine and the define LIBA52_DJBFFT Hope this helps

This error is more of a warning than anything else. I should just comment it out in the library. It only means that the library could potentially run faster if I used an accelerated IMDCT transform.

I grabbed your sample; I will look into it.

09/19/06 18:29:17 changed by gbooker

  • status changed from assigned to closed.
  • resolution set to fixed.

(In [26]) For some odd reason, I thought the buffer size was set by core audio. Oh well, I was wrong. Quadrupled the size of the buffer so it can accept more data at once.

Fixes #9

(follow-up: ↓ 8 ) 02/17/07 14:19:48 changed by leon <leon@isylum.org>

I have a number of video+AC3 sources encoded exactly the same way as described at the start of this ticket.

I am running a52codec 1.7.2 and am experiencing exactly the same symptoms as described here. Seems like increasing the buffer size was an incomplete fix.

I have 2.16 GHz MacBook? Pro.

Same encoded files play perfectly fine with VLC, just not with QT+Perian+a52codec...

02/17/07 14:22:15 changed by leon <leon@isylum.org>

Ermm. I mean a52code 0.7.2.

(in reply to: ↑ 6 ) 02/18/07 15:13:02 changed by gbooker

Replying to leon <leon@isylum.org>:

I have a number of video+AC3 sources encoded exactly the same way as described at the start of this ticket.

Can you provide a sample so I can test further?