[Mplayer-cvslog] CVS: main/DOCS/tech tech-eng.txt,1.18,1.19 tech-hun.txt,1.12,1.13
Winner of tha face compo
gabucino at mplayer.dev.hu
Fri Feb 8 14:55:06 CET 2002
Update of /cvsroot/mplayer/main/DOCS/tech
In directory mplayer:/var/tmp.root/cvs-serv647/tech
Modified Files:
tech-eng.txt tech-hun.txt
Log Message:
applied patch from Andres Johansson
Index: tech-eng.txt
===================================================================
RCS file: /cvsroot/mplayer/main/DOCS/tech/tech-eng.txt,v
retrieving revision 1.18
retrieving revision 1.19
diff -u -r1.18 -r1.19
--- tech-eng.txt 15 Jan 2002 00:24:57 -0000 1.18
+++ tech-eng.txt 8 Feb 2002 13:54:57 -0000 1.19
@@ -273,11 +273,64 @@
all the bytes, it has to give back how many have been used (copied to
buffer).
-static int get_delay();
- Has to return how many bytes are in the audio buffer. Be exact, if possible,
- since the whole timing depends on this! In the worst case, return the size
- of the buffer.
+static float get_delay();
+ Returns how long time it will take to play the data currently in the
+ output buffer. Be exact, if possible, since the whole timing depends
+ on this! In the worst case, return the maximum delay.
!!! Because the video is synchronized to the audio (card), it's very important
-!!! that the get_space and get_delay functions be correctly implemented!
+!!! that the get_space and get_delay functions are correctly implemented!
+
+6.a audio plugins
+ Audio plugins are used for processing the audio data before it
+ reaches the soundcard driver. A plugin can change the following
+ aspects of the audio data stream:
+ 1. Sample format
+ 2. Sample rate
+ 3. Number of channels
+ 4. The data itself (i.e. filtering and other sound effects)
+ 5. The delay (almost all plugins does this)
+ The plugin interface is implemented as a pseudo device driver with
+ the catchy name "plugin". The plugins are executed sequentially
+ ordered by the "-aop list=plugin1,plugin2,..." command line switch.
+ To add plugins add an entry in audio_plugin.h the makefile and
+ create a source file named "pl_whatever.c". Input parameters are
+ added to audio_plugin.h and to cfg-mplayer.h. A good starting point
+ for writing plugins is pl_delay.c. Below is a description of what
+ the functions does:
+
+static int control(int cmd, int arg);
+ This is for reading/setting plugin-specific and other special
+ parameters and can be used for keyboard input for example. All
+ plugins bust respond to cmd=AOCONTROL_PLUGIN_SET_LEN which is part
+ of the initialization of the plugin. When this command is received
+ the parameter pl_delay.len will contain the maximum size of data the
+ plugin can produce. This can be used for calculating and allocating
+ buffer space for the plugin. Before the function exits the parameter
+ pl_delay.len must be set to the maximum data size the plugin can
+ receive. Return CONTROL_OK for success and CONTROL_ERROR for fail,
+ other control codes are found in audio_out.h.
+
+static int init();
+ This function is for initializing the plugin, it is called once
+ before the playing is started. In this function the plugin can read
+ AND write to the ao_plugin_data struct to determine and set input
+ and output parameters. It is important to write to the
+ ao_plugin_data.sz_mult and ao_plugin_data.delay_fix parameters if
+ the plugin changes the data size or adds delay. Return 0 for fail
+ and 1 for success.
+
+static void uninit()
+ Called before mplayer exits. Used for deallocating dynamic buffers.
+
+static void reset()
+ Called during reset can be used to empty buffers. Mplayer calls this
+ function when pause is pressed.
+
+static int play()
+ Called for every block of audio data sent through the plugin. This
+ function should be optimized for speed. The incoming data is found
+ in ao_plugin_data.data having length ao_plugin_data.len. These two
+ parameters should be changed by the plugin. Return 1 for success and
+ 0 for fail.
Index: tech-hun.txt
===================================================================
RCS file: /cvsroot/mplayer/main/DOCS/tech/tech-hun.txt,v
retrieving revision 1.12
retrieving revision 1.13
diff -u -r1.12 -r1.13
--- tech-hun.txt 11 Aug 2001 17:05:35 -0000 1.12
+++ tech-hun.txt 8 Feb 2002 13:54:57 -0000 1.13
@@ -285,10 +285,12 @@
hanem azt kell visszaadnia, mennyit használt fel (másolt a bufferbe).
static int get_delay();
- Vissza kell adja, hogy hány byte várakozik az audio bufferben. lehetõleg
- minél pontosabban, mert ettõl függ az egész idõzítés!
- Legrosszabb esetben adja vissza a buffer méretét!
+ Visszaadja meddig fog tartani az éppen az audio bufferben levõ adat
+ lejátszása. Lehetõleg minél pontosabban, mert ettõl függ az egész idõzítés!
+ Legrosszabb esetben adja vissza a maximális idõzítést.
!!! Mivel a kép a hanghoz (hangkártyához) van szinkronizálva, így nagyon fontos,
!!! hogy a get_space ill. get_delay függvények korrektül legyenek megírva!
+6.a Audio plugin-ek
+ Remélem tudsz angolul.
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