The VideoLAN Forums

I have VLC latest version (when I click 'check for updates').

I am recording TV using a digital tuner and NextPVR.

The recordings are playing fine with Windows Media Player.

But VLC player plays only the video, no audio and complains with a pop-up:
Codec not supported:
VLC could not decode the format "AC-3" (No description for this codec)

Are there any codecs to fix this?

Can you provide some logs ? (Tools > Messages > verbosity 2 before starting playback)

We do support AC-3. Maybe it's connected through HDMI and trying to decode through that.

Thanks for your help. I see this in the log:

mp4 warning: cannot free box AC-3, type unknown
...
core error: Codec `AC-3' (No description for this codec) is not supported.
core debug: killing decoder fourcc `AC-3', 0 PES in FIFO

From what I can see, the 'AC-3' is not recognized in the log:
core debug: auto hiding mouse cursor
core debug: adding item `The.Flash.S04E14.Subject.9.mp4' ( file:///E:/Videos/TV%20shows/The%20Flash/The.Flash.S04E14.Subject.9.mp4 )
core debug: control: stopping input
core debug: incoming request - stopping current input
core debug: finished input
core debug: removing module "avcodec"
avcodec debug: ffmpeg codec (MPEG-1/2 Video) stopped
core debug: killing decoder fourcc `mpgv', 0 PES in FIFO
core debug: Creating an input for 'The.Flash.S04E14.Subject.9.mp4'
core debug: saving a free vout
core debug: reusing provided vout
qt4 debug: Qt: Fullscreen state changed
core debug: removing module "mp4"
mp4 debug: freeing all memory
mp4 warning: cannot free box AC-3, type unknown
mp4 warning: cannot free box text, type unknown
core debug: removing module "record"
core debug: removing module "filesystem"
core debug: Program doesn't contain anymore ES
core debug: incoming request - stopping current input
core debug: dead input
core debug: processing request item: The.Flash.S04E14.Subject.9.mp4, node: Playlist, skip: 0
core debug: rebuilding array of current - root Playlist
core debug: rebuild done - 2 items, index 1
core debug: starting playback of the new playlist item
core debug: resyncing on The.Flash.S04E14.Subject.9.mp4
core debug: The.Flash.S04E14.Subject.9.mp4 is at 1
core debug: creating new input thread
core debug: Creating an input for 'The.Flash.S04E14.Subject.9.mp4'
core debug: requesting art for The.Flash.S04E14.Subject.9.mp4
...

Further below:
core debug: using demux module "mp4"
core debug: looking for a subtitle file in E:\Videos\TV shows\The Flash\
core debug: looking for decoder module matching "any": 43 candidates
avcodec debug: CPU flags: 0x010053db
avcodec debug: trying to use direct rendering
avcodec debug: allowing 4 thread(s) for decoding
avcodec debug: avcodec codec (MPEG-1/2 Video) started
core debug: using decoder module "avcodec"
core debug: looking for decoder module matching "any": 43 candidates
mft error: Could not find suitable MFT decoder
core debug: no decoder modules matched
core error: Codec `AC-3' (No description for this codec) is not supported.
core debug: killing decoder fourcc `AC-3', 0 PES in FIFO
core debug: looking for meta reader module matching "any": 2 candidates

Just to add more information. The mp4 file was created from an over the air recording (file.ts) converted to a file.mp4 using the following:
(3.4.2-win64) ffmpeg.exe -i file.ts -codec copy file.mp4

` qt4 debug: Qt: Fullscreen state changed` it seems you're using VLC 2.2. Can you try with VLC 3.0 ?

I got the same result with the version 3.

Here is part of the log for a similar recording (I removed some entries that did not look relevant):
main debug: incoming request - stopping current input
main debug: Creating an input for preparsing 'Krypton.S01E01.Pilot.mp4'
main debug: killing decoder fourcc `mpgv'
main debug: removing module "avcodec"
main debug: saving a free vout
main debug: reusing provided vout
main debug: removing module "mp4"
mp4 debug: freeing all memory
main debug: Program doesn't contain anymore ES
main debug: removing module "record"
main debug: removing module "cache_read"
main debug: removing module "filesystem"
main debug: dead input
main debug: processing request item: Krypton.S01E01.Pilot.mp4, node: Playlist, skip: 0
main debug: rebuilding array of current - root Playlist
main debug: rebuild done - 2 items, index 1
main debug: starting playback of new item
main debug: resyncing on Krypton.S01E01.Pilot.mp4
main debug: Krypton.S01E01.Pilot.mp4 is at 1
main debug: creating new input thread
main debug: Creating an input for 'Krypton.S01E01.Pilot.mp4'
main debug: requesting art for new input thread
main debug: looking for meta fetcher module matching "any": 1 candidates
main debug: using timeshift granularity of 50 MiB
main debug: using timeshift path: C:\Users\paul\AppData\Local\Temp
main debug: `file:///E:/Videos/TV%20shows/Krypton/Krypton.S01E01.Pilot.mp4' gives access `file' demux `any' path `/E:/Videos/TV%20shows/Krypton/Krypton.S01E01.Pilot.mp4'
main debug: creating demux: access='file' demux='any' location='/E:/Videos/TV%20shows/Krypton/Krypton.S01E01.Pilot.mp4' file='E:\Videos\TV shows\Krypton\Krypton.S01E01.Pilot.mp4'
main debug: looking for access_demux module matching "file": 15 candidates
main debug: no meta fetcher modules matched
main debug: looking for art finder module matching "any": 2 candidates
main debug: no access_demux modules matched
main debug: creating access: file:///E:/Videos/TV%20shows/Krypton/Krypton.S01E01.Pilot.mp4
main debug: (path: E:\Videos\TV shows\Krypton\Krypton.S01E01.Pilot.mp4)
main debug: looking for access module matching "file": 25 candidates
main debug: using access module "filesystem"
main debug: looking for stream_filter module matching "prefetch,cache_read": 24 candidates
main debug: using stream_filter module "cache_read"
main debug: looking for stream_filter module matching "any": 24 candidates
main debug: no art finder modules matched
main debug: looking for meta fetcher module matching "any": 1 candidates
main debug: no meta fetcher modules matched
main debug: looking for art finder module matching "any": 2 candidates
qt debug: IM: Deleting the input
main debug: no art finder modules matched
main debug: no stream_filter modules matched
main debug: looking for stream_directory module matching "any": 1 candidates
main debug: no stream_directory modules matched
main debug: attachment of directory-extractor failed for file:///E:/Videos/TV%20shows/Krypton/Krypton.S01E01.Pilot.mp4
main debug: looking for stream_filter module matching "record": 24 candidates
main debug: using stream_filter module "record"
main debug: creating demux: access='file' demux='any' location='/E:/Videos/TV%20shows/Krypton/Krypton.S01E01.Pilot.mp4' file='E:\Videos\TV shows\Krypton\Krypton.S01E01.Pilot.mp4'
main debug: looking for demux module matching "mp4": 55 candidates
...
avcodec debug: using ffmpeg Lavc58.6.103
avcodec debug: CPU flags: 0x000853db
avcodec debug: allowing 5 thread(s) for decoding
avcodec debug: codec (mpeg2video) started
main debug: using video decoder module "avcodec"
main debug: looking for audio decoder module matching "any": 23 candidates
mft error: Could not find suitable MFT decoder
main debug: no audio decoder modules matched
main error: Codec `AC-3' (No description for this codec) is not supported.
main debug: killing decoder fourcc ` '
main debug: looking for meta reader module matching "any": 2 candidates

I have this problem too.

Anyone has a solution?

File has invalid AC3 mapping in ISOBMFF.
A standard mapping exists for AC3 in mp4, but obviously someone (NextPVR?) decided again to do his own crap.

Provide sample.

Where would I upload a sample?
Is there a fix using ffmpeg for this since I am already converting from .ts to .mp4

Where would I upload a sample?
Is there a fix using ffmpeg for this since I am already converting from .ts to .mp4

Anywhere

you mean that's produced by ffmpeg ? dubious

I have uploaded it here:
http://www.filedropper.com/robinlerobot2018031408000815

Thanks.

Note that it is not the same file since it was 8GB. But I found a smaller one 50MB that gives the same error message.

Yes, this is an output from ffmpeg. I have posted the parameters above.

Note that I just tried an original .ts file and the sound plays fine using VLC.

Any updates on this issue?
I have uploaded the file a while ago.

Where would I upload a sample?
Is there a fix using ffmpeg for this since I am already converting from .ts to .mp4

Anywhere

you mean that's produced by ffmpeg ? dubious

I have uploaded a new sample here:
http://www.filedropper.com/nightgallery ... adeaddruid

I have uploaded a new sample here:
http://www.filedropper.com/nightgallery ... adeaddruid

What's the ffmpeg version ? current ffmpeg can't produce that kind of broken sample entry.

I have uploaded a new sample here:
http://www.filedropper.com/nightgallery ... adeaddruid

What's the ffmpeg version ? current ffmpeg can't produce that kind of broken sample entry.

The version I am using is:
ffmpeg-3.4.2-win64-static

should still not :/
http://git.videolan.org/?p=ffmpeg.git;a ... /3.4#l6516

should still not :/
http://git.videolan.org/?p=ffmpeg.git;a ... /3.4#l6516

I am hoping this is not a case sensitive check. The error I am getting is upper case "AC-3".

What is strange is that Windows Media Player plays it fine so the audio stream is probably ok.

So what would be the next step?

It seems to be a metadata issue. Add to the ffmpeg command line.