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.
+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. 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).
+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 -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!On Solaris, use the SUN audio driver with the
- -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.| 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 | |
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.
- hdparm -u1 /dev/cdrom (man hdparm). This is
- generally beneficial and described in more detail in the
- CD-ROM section.
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.
+ +| 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 32k |
+ 48 | +
| 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. | +
Feedback to this document is welcome. Please tell us how MPlayer and your sound card(s) worked together.
@@ -474,7 +543,7 @@g1:g2:g3...g10-12 and +12
+ - are floating point numbers between
-12 and +12
representing the gain in dB for each frequency band.
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 -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 @@
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:
- 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.