AAC audio decoding problem with FFDShow

[psme]

Hi,

I'm trying AAC audio decoding with FFDShow with some serious problem on those clips with mixed AAC 2.0 and AAC 5.1 sections.

Clip starts in AAC 2.0, then switch to AAC 5.1, FFDShow AAC decoding is fine in the beginning with AAC 2.0 but once reach AAC 5.1 section, there is lots of static noise in Left/Right channels and the decoding does not auto switch to 5.1 output.

Clip starts in AAC 5.1, then switch to AAC 2.0, AAC 5.1 decoding is fine with full 5.1 channels output in the beginning but only silent in AAC 2.0 section.

Tried both a old (ffdshow-20060604-rev2546.exe) and new (ffdshow-rev705_20061222_clsid.exe) version with same result.

regards,

Li On

[_xxl]

Please provide a sample.

[psme]

Thanks for the help.

I attached 2 samples. I hope the forum will show them. Both samples are around 9 seconds long to fit forum max 300K attachment size. The switch from 2.0 to 5.1 or 5.1 to 2.0 is around in the mid way.

It was from Japanese HDTV broadcast which uses AAC for audio. I demuxed the transport stream to post the AAC sample only.

GraphEdit can play the sample using FFDShow Audio decoder, with AAC Parser filter installed.

On the 2.0 to 5.1 sample, 2.0 section plays fine in the beginning but in the mid way when the track switch to 5.1 the FFDShow audio output becomes very noisy and distorted.

On the 5.1 to 2.0 sample, 5.1 section plays fine in the beginning with full 5.1 channel output but no audio output when the 2.0 section start. In GraphEdit the playback simply stopped at the mid point while in the actual transport stream playback the audio becomes silent during 2.0 section.

Both samples play fine in WinAmp 2.81 from start to end with no effect on the channel change.

I also tried CoreAAC, it plays fine from 2.0 to 5.1 switch with correct 5.1 output without any noise/distortion. But it also acts the same of silent output when switching from 5.1 to 2.0 in the same sound track.

The reason for such 2.0 to 5.1 and back AAC decoding is because the HDTV program will use 5.1 track for the main show and drop to 2.0 in commerical so the audio switch in and out between 2.0 and 5.1.

I can give you more sample if needed. Thanks in advance.

regards,

Li On

[KoD]

What player are you using ? What is the container for those two aac streams : mkv, mp4 ? If you are using MPC, are you using MPC's internal splitters or Haali's external one ?

[psme]

I use ZoomPlayer. The AAC track is from Japanese HDTV transport stream with 1080i MPEG2 video. I tried a few splitters such as Haali, OpenSource MPEG File etc with same result.

Player, splitter, container doesn't matter IMO. As the problem acts the same in GraphEdit with the most basic FileSource->AAC parser->FFDShow Audio decoder->DirectSound/WaveOut playback.

regards,

Li On

[Guest]

Large files like that should be uploaded to a free hosting site rather than attached.

[psme]

Understood. The files I attached should show the issue. If more sample is needed, I will upload to a file hosting site.

regards,

Li On

[psme]

Sorry for repeat post.

I see my attached samples are still in "Attachments Pending Approval" status. Can anyone get the samples to check? How long will it take for "Approval"? Or that won't happen and I need to put the samples at other hosting site, now?

Thanks in advance.

regards,

Li On

[foxyshadis]

Approval in a timely fashion often means asking a mod. But since neuron2 didn't approve them, he might mean they won't be approved and have to be uploaded elsewhere, for bandwidth reasons. (Or maybe since he's not a mod in this forum, he can't, I don't know. =p)

[psme]

Ok, hope this work:

AAC samples (http://filehost.justfreespace.com/197023)

regards,

Li On