Audio corruption on N1000

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1

I have a couple user reports of audio corruption during video playback for my channel. They have: Roku HD, model N1000, Software version 2.6 build 693

I have: Roku HD model N1100, Software version 2.6 build 693

An example file is:
http://s3.amazonaws.com/khanvideo/publi … D24QJ0.mp4

For me it works fine, they report that video works but audio is broken.

Here’s what ffmpeg says about the file:

Seems stream 0 codec frame rate differs from container frame rate: 65535.00 (65535/1) → 30.00 (30/1)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from ‘bAerID24QJ0.mp4’:
Duration: 00:07:32.26, start: 0.000000, bitrate: 188 kb/s
Stream #0.0(und): Video: mpeg4, yuv420p, 320x240 [PAR 1:1 DAR 4:3], 30 tbr, 65535 tbn, 65535 tbc
Stream #0.1(und): Audio: ac3, 44100 Hz, stereo, s16

Any clues? I can re-encode my video files with different flags and options, but I don’t have a N1000 to test against.

2

It doesn’t have any sound on either one of my boxes. Not only that, but it doesn’t have sound on two different computers running different versions of Windose and using Windows Media Player or Media Player Classic (with AAC codecs). If I look at the “details” using explorer, the Audio section lists a bit rate, but nothing for the number of channels or sample rate (which is odd). Additionally, if I use HandBrake to convert your video it gives all sorts of audio sync issues and produces something without much in the way of sound.

It does play with sound using VLC.

I hate to use Windows as a benchmark, but I guess if you can make it happy you’d have a better chance of things working.

-JT

3

Thanks for the reply, renojim.

I tried reencoding one of the files using aac instead of ac3. That one works on my N1100 and also plays in Windows. Could you try it on you roku? It is in the public Khan academy channel, under “other” - “ck12.org worked examples”. It is the last episode, named “secret audio test”.

If that one works on the N1000 I’ll reencode everything with those options.

4

Oops! I actually confused AAC and AC3 in my previous post. Sorry about that.

Anyway, it looks and sounds great!

-JT