MPEG-2 file with AC3 5.1 audio: no audio (neither in current video playback, nor after encode), but plays okay in QuickTime X

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chuckles67 Author

Level 1

13 points

MPEG-2 file with AC3 5.1 audio: no audio (neither in current video playback, nor after encode), but plays okay in QuickTime X

Mavericks 10.9.3

Latest Mac Mini, 8GB RAM, two 256GB SSD

Compressor 4.1.1

I have an MPEG-2 file with AC3 5.1 audio which plays in QuickTime X as expected.

I have a second MacBook Pro with Compressor 4.1.1, where the audio is fine - both as current video playback of the source, and post-encode using Apple Devices HD (best quality) setting.

However in the Mac Mini Compressor there is no audio (neither in current video playback of the source, nor after encode using Apple Devices HD (best quality) setting).

Troubleshooting

- main difference between machines is the Mac Mini has Elgato software (EyeTV and Game Capture HD)

- I've checked the QuickTime components are same on both machines, except for EyeTV audio component on Mac Mini

- there are no plug-in audio components

- I've repaired permissions using Disk Utility

- I moved Compressor to trash, deleted compressor plist files, and reinstalled

Posted on Jun 26, 2014 1:56 PM

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Answer 1

Russ H

Level 7

22,432 points

Jun 27, 2014 4:35 AM in response to chuckles67

Nothing immediately comes to mind.

Could you open this up in MediaInfo or VideoSpec and post a screenshot of the report?

Russ

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Answer 2

chuckles67 Author

Level 1

13 points

Jun 27, 2014 1:34 PM in response to Russ H

MediaInfo trace:

General

Complete name : /Users/tester/Movies/export-tests/test24trailer.mpg

Format : MPEG-PS

File size : 12.9 MiB

Duration : 12s 576ms

Overall bit rate mode : Variable

Overall bit rate : 8 614 Kbps

Video

ID : 224 (0xE0)

Format : MPEG Video

Format version : Version 2

Format profile : Main@High

Format settings, BVOP : Yes

Format settings, Matrix : Default

Format settings, GOP : Variable

Duration : 12s 533ms

Bit rate mode : Variable

Bit rate : 7 995 Kbps

Maximum bit rate : 38.8 Mbps

Width : 1 280 pixels

Height : 720 pixels

Display aspect ratio : 16:9

Active Format Description : Letterbox 16:9 image

Frame rate : 59.940 fps

Color space : YUV

Chroma subsampling : 4:2:0

Bit depth : 8 bits

Scan type : Progressive

Compression mode : Lossy

Bits/(Pixel*Frame) : 0.145

Stream size : 11.9 MiB (92%)

Audio

ID : 189 (0xBD)-128 (0x80)

Format : AC-3

Format/Info : Audio Coding 3

Mode extension : CM (complete main)

Format settings, Endianness : Big

Muxing mode : DVD-Video

Duration : 12s 576ms

Bit rate mode : Constant

Bit rate : 448 Kbps

Channel(s) : 6 channels

Channel positions : Front: L C R, Side: L R, LFE

Sampling rate : 48.0 KHz

Bit depth : 16 bits

Compression mode : Lossy

Stream size : 688 KiB (5%)

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Answer 3

chuckles67 Author

Level 1

13 points

Jun 27, 2014 4:47 PM in response to chuckles67

I found the difference: the machine that works has an AC-3 A52codec.component file, whereas the machine that doesn't work does not. Copying the component across fixed this.

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