Opened 13 years ago

Closed 13 years ago

#2109 closed patch (fixed)

AC3 passthru problems with OSS driver.

Reported by: ivan-mythtv@… Owned by: danielk
Priority: minor Milestone: 0.21
Component: mythtv Version: head
Severity: low Keywords:
Cc: Ticket locked: no

Description

When using the nvidia supplied nvsound oss driver and a nForce2 ac3 passthru results in static. The audio device is being opend without checking audio_passthru and setting appropriate format in audiooutputoss.cpp. Attached patch checks if the sound card should be set for ac3(dts) passthru and sets format to be AFMT_AC3 overriding previous pcm format values.

Attachments (2)

oss_spdif_patch.diff (445 bytes) - added by ivan-mythtv@… 13 years ago.
OSS ac3 passthru patch
oss_spdif_patch2.diff (670 bytes) - added by anonymous 13 years ago.

Download all attachments as: .zip

Change History (11)

Changed 13 years ago by ivan-mythtv@…

Attachment: oss_spdif_patch.diff added

OSS ac3 passthru patch

comment:1 Changed 13 years ago by danielk

Milestone: unknown
Owner: changed from Isaac Richards to danielk
Severity: mediumlow
Version: head

comment:2 Changed 13 years ago by danielk

Resolution: fixed
Status: newclosed

(In [10718]) Fixes #2109. Adds support for AC3 passthrough audio with OSS drivers.

Some AC3/DTS decoders could work without the AC3 flag being set, but only because it was robust. This just sets the format flag appropriately, since many filters & decoders don't detect digital data robustly.

comment:3 Changed 13 years ago by Stuart Auchterlonie

Milestone: unknown0.20
Resolution: fixed
Status: closedreopened

These changes cause breakage for other users. See the thread

http://mythtv.org/pipermail/mythtv-dev/2006-August/049669.html

comment:4 Changed 13 years ago by danielk

(In [10762]) Refs #2109. Reverts [10718]. This causes problems with OSS output for some people.

This can wait until 0.21, anyone using an audio chipset only supported by OSS audio and a decoder which doesn't autodetect without this can apply the patch manually..

comment:5 Changed 13 years ago by danielk

Milestone: 0.200.21

comment:6 Changed 13 years ago by danielk

Resolution: invalid
Status: reopenedclosed

closing, this patch causes problems for other hardware.

comment:7 Changed 13 years ago by anonymous

Whoops, forgot about this, I cleaned up the patch some, it may fix the problem that was seen earlier. This should work exactly like mplayer now.

Changed 13 years ago by anonymous

Attachment: oss_spdif_patch2.diff added

comment:8 Changed 13 years ago by danielk

Resolution: invalid
Status: closedreopened

comment:9 Changed 13 years ago by danielk

Resolution: fixed
Status: reopenedclosed

(In [11392]) Fixes #2109. Adds support for AC3 passthrough audio with OSS drivers.

This sets the format flag appropriately, since many filters & decoders don't detect digital data robustly.

In addition to the code that was added in [10718] and reverted in [10762] this adds a sanity check to make sure the drivers support AC3 passthrough before setting the passthrough bit. Some drivers support AC3 passthough, but don't support the official OSS API for it and die a horrible death when you set the AC3 bit.

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