Opened 19 years ago
Closed 19 years ago
Last modified 10 years ago
#287 closed enhancement (fixed)
XvMC decoding, MPEG2 stream recognized as MPEG1
| Reported by: | Owned by: | danielk | |
|---|---|---|---|
| Priority: | minor | Milestone: | 0.19 |
| Component: | mythtv | Version: | head |
| Severity: | low | Keywords: | XvMC MPEG1 MPEG2 |
| Cc: | Ticket locked: | no |
Description (last modified by )
Whenever a XvMC is used, it sometimes works and sometimes it does not, I have found that when the same DVB-C (ts) stream is recognized as MPEG1 the XvMC-hardware decoding does not work ( AVFD: Stream #0, has id 0x33 codec id MPEG1VIDEO, type Video at 0x0x82a95a0 ), but when the same stream is recognized as MPEG2 everything works.( AVFD: Stream #0, has id 0x215 codec id MPEG2VIDEO, type Video at 0x0x827e940 )
Debug output attached.
Attachments (3)
Change History (11)
comment:1 Changed 19 years ago by
| Description: | modified (diff) |
|---|---|
| Owner: | changed from Isaac Richards to danielk |
| Priority: | critical → minor |
| Status: | new → assigned |
comment:2 Changed 19 years ago by
| Milestone: | → 0.19 |
|---|---|
| Severity: | medium → low |
| Type: | defect → enhancement |
comment:3 Changed 19 years ago by
But why the stream is sometimes recognized as MPEG1 and sometimes MPEG2. This happens on all of my channels. That's a little wierd if it's a broadcasters problem..
Changed 19 years ago by
| Attachment: | debug-worked.txt added |
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debug txt-files, for easier reading (working)
Changed 19 years ago by
| Attachment: | mpeg1-hack.patch added |
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comment:4 Changed 19 years ago by
| Description: | modified (diff) |
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Can you try the attached patch, it should fix the problem without breaking anything if I have diagnosed the problem correctly.
comment:5 Changed 19 years ago by
| Resolution: | → worksforme |
|---|---|
| Status: | assigned → closed |
works like a charm with the XvMC on, and all of the other freezes went away too, and channel locks every time now. Great work that little hack.
comment:6 Changed 19 years ago by
| Resolution: | worksforme → fixed |
|---|
Some channels report MPEG1 when they are really transmitting MPEG2.
This forces MythTV to treat all MPEG1 streams as MPEG2 streams when using XvMC. Since libav only supports MPEG2 XvMC and not MPEG1 XvMC this shouldn't hurt anyone. Theoretically someone might have MPEG1 XvMC acceleration and not MPEG2 XvMC accelleration, but even so we wouldn't support XvMC on that configuration anyway bwcause of the libav limitation.
It looks like the transmitter is marking an MPEG-2 stream as a MPEG-1 stream, since libav can handle MPEG-1 in the MPEG-2 decoder it should be easy to work around this problem with the channel. I just want to check if this will break libmpeg first.
But you should notify the engineers at that broadcaster of their problem.