From 87de8a8f9432075eb6f997d1d635b2e306d1e716 Mon Sep 17 00:00:00 2001
From: diego Fact is, Linux sound card drivers have compatibility problems. The cause
- is that MPlayer uses a feature that well coded audio drivers implement to
- maintain audio/video sync. Regrettably, some driver authors do not care about
- this function, it is not needed for playing MP3s or for sound effects. Other media players like aviplay or xine possibly work out-of-the-box with
- these drivers because they use "simple" methods with internal timing. A note:
- time showed their methods aren't AS efficient as MPlayer's. With a correctly written audio driver MPlayer will never create audio related
- A/V desynchronisation, unless your file is badly broken. Some options to work
- around these problems are described in the man page). Linux sound card drivers have compatibility problems. This is because MPlayer
+ relies on an in-built feature of properly coded sound drivers that
+ enable them to maintain correct audio/video sync. Regrettably, some driver
+ authors don't take the care to code this feature since it is not needed for
+ playing MP3s or sound effects. Other media players like aviplay
+ or xine possibly work
+ out-of-the-box with these drivers because they use "simple" methods with
+ internal timing. Measuring showed that their methods are not as efficient
+ as MPlayer's. Using MPlayer with a properly written audio driver will never result
+ in A/V desyncs related to the audio, except only with very badly created
+ files (check the man page for workarounds). If you happen to have a bad audio driver, try the On Solaris, use the SUN audio driver with the
- On Linux, a 2.4.x kernel is highly recommended. Kernel 2.2 is not tested. If the sound clicks when playing from CD-ROM, turn on IRQ unmasking, e.g.
- Linux sound drivers are primarily provided by the free version of OSS. These
+ drivers have been superceded by ALSA
+ (Advanced Linux Sound Architecture) in the 2.5 development series. If your
+ distribution does not already use ALSA you may wish to try their drivers if
+ you experience sound problems. ALSA drivers are generally superior to OSS in
+ compatibility, performance and features. But some sound cards are only
+ supported by the commercial OSS drivers from
+ 4Front Technologies. They also support
+ several non-Linux systems. Feedback to this document is welcome. Please tell us how MPlayer
and your sound card(s) worked together. MPlayer has support for audio plugins. Audio plugins can be used for
- changing the properties of the audio data before the sound reaches the sound
+ MPlayer has support for audio plugins. Audio plugins can be used to
+ change the properties of the audio data before it reaches the sound
card. They are enabled using the would set the output frequency of the resample plugin to 44100Hz and the
output format of the format plugin to AFMT_U8. Currently audio plugins can not be used in MEncoder. Currently audio plugins cannot be used in MEncoder. MPlayer fully supports up/downsampling of the sound. This plugin can
be used if you have a fixed frequency sound card or if you are
stuck with an old sound card that is only capable of max 44.1kHz.
- Whether is usage of this plugin is necessary or not, is autodetected.
- This plugin has one switch:
- -autosync
option, it should sort out your problems. See the man page for detailed
@@ -67,94 +70,160 @@
default). If you experience glitches, halts or anything out of the
ordinary, try -ao sdl
(NOTE: You need to have SDL libraries
and header files installed). The SDL audio driver helps in a lot of cases
- and also supports ESD and ARTS. (ESD is the sound daemon
- from GNOME, ARTS is from KDE.)
+ and also supports ESD (GNOME) and ARTS (KDE).
-ao alsa5
, since ALSA 0.5 has buggy OSS emulation code, and
will crash MPlayer with a message like this:
DEMUXER: Too many (945 in 8390980 bytes) video packets in the buffer!
-ao sun
option, otherwise neither video nor audio will work.-ao sun
option,
+ otherwise neither video nor audio will work.hdparm -u1 /dev/cdrom
(man hdparm
). This is
+ generally beneficial and described in more detail in the
+ CD-ROM section.2.3.2.2 Sound Card experiences, recommendations
-
-
-
- VIA onboard chipset (via82cxxx) 48kHz only
-
- Driver: from the
- gkernel project
- Aureal Vortex 2
- OSS: no driver
- OSS/Pro: OK
- ALSA: no driver
- Max kHz: 48
- Driver: aureal.sourceforge.net
-
- Driver2: from Pontscho's page
- (buffer size increased to 32k)
- GUS PnP
- OSS: no driver
- OSS/Pro: OK
- ALSA: OK
-
- Max kHz: 48
- SB Live!
- OSS: Analog OK, SP/DIF not working
- ALSA: Both OK
-
- Max kHz: 192
- SB AWE 64
- OSS: max 44kHz
- ALSA: 48kHz sounds bad
-
- Max kHz: 48
- Gravis UltraSound ACE
- OSS: not OK
- ALSA: OK
-
- Max kHz: 44
- Gravis UltraSound MAX
- OSS: OK
- ALSA: OK (?)
-
- Max kHz: 48
- ESS 688
- OSS: OK
- ALSA: OK (?)
-
- Max kHz: 48
- C-Media cards (which ones?)
- OSS: not OK (hissing) (?)
- ALSA: OK (?)
-
- Max kHz: ?
- Yamaha cards (*ymf*)
- OSS: not OK (?) (maybe -ao sdl
)
- ALSA: OK only with ALSA 0.5 with OSS emulation AND -ao sdl
(!) (?)
-
- Max kHz: ?
- Cards with envy24 chips (like Terratec EWS88MT)
- OSS: ?
- OSS/Pro: OK
- ALSA: ?
-
- Max kHz: ?
- PC Speaker or DAC
- OSS: OK (Use the SDL driver: -ao sdl
)
- ALSA: no driver
- Max kHz: The driver emulates 44.1, maybe more.
-Driver: ftp://ftp.infradead.org/pub/pcsp hdparm -u1 /dev/cdrom
(man hdparm
). This is
- generally beneficial and described in more detail in the
- CD-ROM section.
+
+
+
+
+ SOUND CARD
+ DRIVER
+ Max kHz
+
+
+
+ OSS/Free
+ ALSA
+ OSS/Pro
+ other
+
+
+
+ VIA onboard (686/A/B, 8233, 8235)
+ via82cxxx_audio
+ snd-via82xx
+
+
+ 4-48 kHz or 48 kHz only, depending on the chipset
+
+
+
+ Aureal Vortex 2
+ none
+ none
+ OK
+ Linux Aureal Drivers
+
+ buffer size increased to 32k48
+
+
+
+ GUS PnP
+ none
+ OK
+ OK
+
+ 48
+
+
+
+ SB Live!
+ Analog OK, SP/DIF not working
+ Both OK
+
+
+ 192
+
+
+
+ SB AWE 64
+ max 44kHz
+ 48kHz sounds bad
+
+
+ 48
+
+
+
+ Gravis UltraSound ACE
+ not OK
+ OK
+
+
+ 44
+
+
+
+ Gravis UltraSound MAX
+ OK
+ OK (?)
+
+
+ 48
+
+
+
+ ESS 688
+ OK
+ OK (?)
+
+
+ 48
+
+
+
+ C-Media cards (which ones?)
+ not OK (hissing) (?)
+ OK (?)
+
+
+ ?
+
+
+
+ Yamaha cards (*ymf*)
+ not OK (?) (maybe
+ -ao sdl
)OK only with ALSA 0.5 with OSS emulation AND
+
+ -ao sdl
(!) (?)
+
+ ?
+
+
+
+ Cards with envy24 chips (like Terratec EWS88MT)
+ ?
+ ?
+ OK
+
+ ?
+
+
+
+PC Speaker or DAC
+ OK (Use the SDL driver:
+ -ao sdl
)none
+
+ Linux PC speaker OSS driver
+ The driver emulates 44.1, maybe more.
+
@@ -591,8 +660,8 @@
g1:g2:g3...g10
-12
and
+12
+ -12
and +12
representing the gain in dB for each frequency band.2.3.2.4 Audio plugins (deprecated)
--aop
switch which takes a
list=plugin1,plugin2,...
argument. The list
argument
is required and determines which plugins should be used and in which order they
@@ -614,7 +683,7 @@
2.3.2.4.1 Up/Downsampling
@@ -622,11 +691,10 @@
fout
which is used for setting the desired output sample
- frequency. It defaults to 48kHz, and is given in
- <Hz>.fout
, which is used for setting the
+ desired output sample frequency. The value is given in Hz, and defaults to
+ 48kHz.
Usage: Note that the output frequency should not be scaled up from the default value.
Scaling up will cause the audio and video streams to be played in slow motion
- in addition to audio distortion.
mplayer media.avi -aop list=resample:fout=<required
@@ -634,7 +702,7 @@
If you have a file with a consistent A/V sync fault, use the +/-
+ keys to adjust timings on-the-fly instead. Usage of the OSD is recommended
+ to make this easier.