Opened 17 years ago
Closed 17 years ago
#3608 closed defect (fixed)
Latest ffmpeg sync causes decoded AC3 audio to sound like it is going through a table fan.
| Reported by: | anonymous | Owned by: | Janne Grunau |
|---|---|---|---|
| Priority: | major | Milestone: | 0.21 |
| Component: | mythtv | Version: | head |
| Severity: | high | Keywords: | |
| Cc: | Ticket locked: | no |
Description
I just compiled the latest svn from the trunk and now my decoded AC3 audio sounds like it is going through a table fan, or perhaps an old vhs.
I believe that revision 13655 is the cause because that is the only mention of the AC3 decoder that I know of.
Attachments (2)
Change History (8)
comment:1 Changed 17 years ago by
comment:2 Changed 17 years ago by
| Milestone: | unknown → 0.21 |
|---|---|
| Owner: | changed from Isaac Richards to Janne Grunau |
| Priority: | minor → major |
| Severity: | medium → high |
| Version: | unknown → head |
I hear only occasionally short distorted passages. It is (at least with my recordings) not very noticable. I first thought the input was overmodulated.
Please provide an example, audio only is enough. I'll contact the ffmpeg dev and look if a never version of the patch (and a minor ffmpeg resync) helps.
comment:3 follow-up: 4 Changed 17 years ago by
I believe that I am suffering this effect on 1 stream I receive (ABC TV Canberra). Interestingly I don't observe it on any other stream, not even ABC TV, which has the same content and is on the same multiplex. I have uploaded a 30 second sample file (24MiB) from ABC TV Canberra here:
Changed 17 years ago by
| Attachment: | ac3_final.diff.bz2 added |
|---|
updates the ac3 patch to the final version from 2007-05-07
comment:4 Changed 17 years ago by
Replying to darkstarsword@gmail.com:
I have uploaded a 30 second sample file (24MiB) from ABC TV Canberra here:
I can't reproduce the audio distortions. I don't hear a difference.
Can you please try if the attached patch fixes the audio decoding? I doubt it but it's worth a try.
If it doesn't help please reply with system details and configure options and output.
Changed 17 years ago by
| Attachment: | ac3_final_13758.diff.bz2 added |
|---|
comment:5 Changed 17 years ago by
I uploaded accidentally an old and unclean patch. Please test only with http://svn.mythtv.org/trac/attachment/ticket/3608/ac3_final_13758.diff.bz2.
comment:6 Changed 17 years ago by
| Resolution: | → fixed |
|---|---|
| Status: | new → closed |
(In [13765]) Fixes #3608. Updates ffmpeg's internal ac3 decoder
This updates the ac3 decoder in our libavcodec copy to the final patch posted on 2007-05-07 by Justin Ruggles pulls also ffmpeg revision 8816 in, since it's need by the patch. Fixes the Audio distortion reported in #3608.
Refs #3634. crashes on x86_32 with debug and release builds
build without ac3_decoder and with liba52bin fixes this. this is a change from the previous ffmpeg which disabled ac3dec and used liba52 only.
changes to configure are --enable-liba52bin --disable-decoder=ac3 --enable-decoder=liba52
liba52 is then an external dependency
This was mentioned in aprevious email my me.