Opened 17 years ago
Closed 17 years ago
#5220 closed defect (fixed)
Any corruption in mpeg transport streams cases loud chirps in ac3 audio
| Reported by: | Owned by: | Anduin Withers | |
|---|---|---|---|
| Priority: | minor | Milestone: | unknown |
| Component: | mythtv | Version: | 0.21-fixes |
| Severity: | medium | Keywords: | |
| Cc: | Ticket locked: | no |
Description
The version of ffmpeg used in 0.21 allows serious full-scale pops and chirps in ac3 audio if there's any corruption in the mpeg ts file (from OTA interference for example).
It appears that in newer versions of ffmpeg libavcodec/ac3dec.c does a crc checksum and drops any bad ac3.
Other details have been posted here:
http://www.gossamer-threads.com/lists/mythtv/dev/330167
I'm attaching a patch I'm using to address this.
Attachments (1)
Change History (4)
Changed 17 years ago by
| Attachment: | mythtv-0.21-ffmpeg_ac3_crc.patch added |
|---|
comment:1 Changed 17 years ago by
| Owner: | changed from Isaac Richards to Anduin Withers |
|---|---|
| Status: | new → accepted |
comment:2 Changed 17 years ago by
comment:3 Changed 17 years ago by
| Resolution: | → fixed |
|---|---|
| Status: | accepted → closed |
Merges [17083] from trunk.
Original commit message:
This imports a modified version of the AC3 CRC check introduced in ffmpeg's revision 11379.
This should eliminate chirp/pop issues when the AC3 data is corrupt.
Thanks to Tom Dexter for this patch. My modifications were only to make it as close to the current ffmpeg code as possible (without importing the new CRC table stuff).
(In [17083]) References #4862, #5220
This imports a modified version of the AC3 CRC check introduced in ffmpeg's revision 11379.
This should eliminate chirp/pop issues when the AC3 data is corrupt.
Thanks to Tom Dexter for this patch. My modifications were only to make it as close to the current ffmpeg code as possible (without importing the new CRC table stuff).