[MPlayer-dev-eng] [PATCH] Proof of concept extrasurround plugin
Kis Gergely
kisg at lme.linux.hu
Thu Apr 4 15:55:45 CEST 2002
Hi,
I promise this is the last patch from me today. I hope Arpi won't ban me for
this.
I added a sochans option for the pl_surround plugin.
Usage:
mplayer -aop list=surround:sochans=6 filename
4 channel output is the default. The nice thing is, that in 4 channel mode
every file plays well. In 6 channel mode the previous problems apply.
Could somebody try it out, and tell me what am I missing?
The patch is attached, and uploaded to mplayerhq/incoming/extrasurround
You can also get it from http://www.inf.bme.hu/~kisg/mplayer
Thanks,
kisg
-------------- next part --------------
? cfg-mplayer.h.kisg4
? extrasurround_kisg4.patch
? libao2/audio_plugin.h.kisg4
? libao2/pl_surround.c.kisg1
? libao2/pl_surround.c.kisg2
Index: cfg-mplayer.h
===================================================================
RCS file: /cvsroot/mplayer/main/cfg-mplayer.h,v
retrieving revision 1.143
diff -u -r1.143 cfg-mplayer.h
--- cfg-mplayer.h 4 Apr 2002 00:00:41 -0000 1.143
+++ cfg-mplayer.h 4 Apr 2002 13:58:14 -0000
@@ -112,6 +112,7 @@
{"volume", &ao_plugin_cfg.pl_volume_volume, CONF_TYPE_INT, CONF_RANGE, 0, 255, NULL},
{"mul", &ao_plugin_cfg.pl_extrastereo_mul, CONF_TYPE_FLOAT, CONF_RANGE, -10.0, 10.0, NULL},
{"softclip", &ao_plugin_cfg.pl_volume_softclip, CONF_TYPE_FLAG, 0, 0, 1, NULL},
+ {"sochans", &ao_plugin_cfg.pl_surround_sochans, CONF_TYPE_INT, CONF_MIN, 0, 0, NULL},
{NULL, NULL, 0, 0, 0, 0, NULL}
};
Index: libao2/audio_plugin.h
===================================================================
RCS file: /cvsroot/mplayer/main/libao2/audio_plugin.h,v
retrieving revision 1.10
diff -u -r1.10 audio_plugin.h
--- libao2/audio_plugin.h 13 Mar 2002 12:32:42 -0000 1.10
+++ libao2/audio_plugin.h 4 Apr 2002 13:58:16 -0000
@@ -38,6 +38,7 @@
int pl_volume_volume; // Initial volume setting
float pl_extrastereo_mul; // Stereo enhancer multiplier
int pl_volume_softclip; // Enable soft clipping
+ int pl_surround_sochans; // Output channels for surround plugin
} ao_plugin_cfg_t;
extern ao_plugin_cfg_t ao_plugin_cfg;
@@ -50,7 +51,8 @@
48000, \
101, \
2.5, \
- 0 \
+ 0, \
+ 4 \
};
// This block should not be available in the pl_xxxx files
Index: libao2/pl_surround.c
===================================================================
RCS file: /cvsroot/mplayer/main/libao2/pl_surround.c,v
retrieving revision 1.9
diff -u -r1.9 pl_surround.c
--- libao2/pl_surround.c 24 Dec 2001 18:54:58 -0000 1.9
+++ libao2/pl_surround.c 4 Apr 2002 13:58:17 -0000
@@ -64,6 +64,7 @@
int passthrough; // Just be a "NO-OP"
int msecs; // Rear channel delay in milliseconds
int16_t* databuf; // Output audio buffer
+ int databuf_len; // Output audio buffer length in samples
int16_t* Ls_delaybuf; // circular buffer to be used for delaying Ls audio
int16_t* Rs_delaybuf; // circular buffer to be used for delaying Rs audio
int delaybuf_len; // delaybuf buffer length in samples
@@ -72,10 +73,14 @@
int rate; // input data rate
int format; // input format
int input_channels; // input channels
+ int output_channels; // output channels
+ float lowp_cutoff; // cutoff freq for the lowpass filter
+ double lowp_A, lowp_B; // parameters for lowpass filter
+ double lowp_outm1; // output for lowpass filter (??)
} pl_surround_t;
-static pl_surround_t pl_surround={0,20,NULL,NULL,NULL,0,0,NULL,0,0,0};
+static pl_surround_t pl_surround={0,20,NULL,0,NULL,NULL,0,0,NULL,0,0,0,0,0,0,0,0};
// to set/get/query special features/parameters
static int control(int cmd,int arg){
@@ -89,9 +94,10 @@
free(pl_surround.databuf); pl_surround.databuf = NULL;
}
// Allocate output buffer
- pl_surround.databuf = calloc(ao_plugin_data.len, 1);
+ pl_surround.databuf_len = ao_plugin_data.len / sizeof(int16_t) / pl_surround.input_channels;
+ pl_surround.databuf = calloc(pl_surround.databuf_len, sizeof(int16_t)*pl_surround.output_channels);
// Return back smaller len so we don't get overflowed...
- ao_plugin_data.len /= 2;
+ // ao_plugin_data.len /= 2;
return CONTROL_OK;
}
return -1;
@@ -113,6 +119,12 @@
return 1;
}
+ if (ao_plugin_cfg.pl_surround_sochans != 4 && ao_plugin_cfg.pl_surround_sochans != 6) {
+ fprintf(stderr, "pl_surround: I'm dumb and can only output 4 or 6 channel sound. Entering passtrough mode.\n");
+ pl_surround.passthrough = 1;
+ return 1;
+ }
+
pl_surround.passthrough = 0;
/* Store info on input format to expect */
@@ -120,9 +132,16 @@
pl_surround.format=ao_plugin_data.format;
pl_surround.input_channels=ao_plugin_data.channels;
+ /* Store info on output channel number */
+ pl_surround.output_channels = ao_plugin_cfg.pl_surround_sochans;
+
+
// Input 2 channels, output will be 4 - tell ao_plugin
- ao_plugin_data.channels = 4;
- ao_plugin_data.sz_mult /= 2;
+// ao_plugin_data.channels = 4;
+// ao_plugin_data.sz_mult /= 2;
+
+ ao_plugin_data.channels = pl_surround.output_channels;
+ ao_plugin_data.sz_mult /= pl_surround.output_channels / pl_surround.input_channels;
// Figure out buffer space (in int16_ts) needed for the 15msec delay
// Extra 31 samples allow for lowpass filter delay (taps-1)
@@ -137,6 +156,16 @@
pl_surround.filter_coefs_surround = calc_coefficients_7kHz_lowpass(pl_surround.rate);
//dump_filter_coefficients(pl_surround.filter_coefs_surround);
//testfilter(pl_surround.filter_coefs_surround, 32, pl_surround.rate);
+
+ pl_surround.lowp_cutoff = 7000;
+ if (pl_surround.lowp_cutoff > pl_surround.rate / 2) {
+ // Cutoff rate must be < sample rate / 2 (Nyquist rate)
+ pl_surround.lowp_cutoff = pl_surround.rate / 2 - 1;
+ }
+ pl_surround.lowp_B = exp ((-2.0 * M_PI * (pl_surround.lowp_cutoff / pl_surround.rate)));
+ pl_surround.lowp_A = 1 - pl_surround.lowp_B;
+ pl_surround.lowp_outm1 = 0.0;
+
return 1;
}
@@ -161,6 +190,7 @@
pl_surround.delaybuf_pos = 0;
memset(pl_surround.Ls_delaybuf, 0, sizeof(int16_t)*pl_surround.delaybuf_len);
memset(pl_surround.Rs_delaybuf, 0, sizeof(int16_t)*pl_surround.delaybuf_len);
+ pl_surround.lowp_outm1 = 0;
}
// The beginnings of an active matrix...
@@ -222,6 +252,26 @@
#else
out[3] = -out[2];
#endif
+ if (pl_surround.output_channels == 6) {
+
+ int32_t avg;
+ double d;
+ avg = (out[0] + out[1]) / 2;
+
+ d = pl_surround.lowp_A * avg + pl_surround.lowp_B * pl_surround.lowp_outm1;
+
+ if (d > 32767L) {
+ d = 32767L;
+ }
+ if (d < -32768L) {
+ d = -32768L;
+ }
+ pl_surround.lowp_outm1 = d;
+ out[5] = d;
+ // Only 4.1 output, center speaker remains silent
+ out[4] = 0;
+ }
+
// calculate and save surround for 20msecs time
#ifdef SPLITREAR
pl_surround.Ls_delaybuf[pl_surround.delaybuf_pos] =
@@ -235,7 +285,7 @@
pl_surround.delaybuf_pos %= pl_surround.delaybuf_len;
// next samples...
- in = &in[pl_surround.input_channels]; out = &out[4];
+ in = &in[pl_surround.input_channels]; out = &out[pl_surround.output_channels];
}
// Show some state
@@ -243,6 +293,6 @@
// Set output block/len
ao_plugin_data.data=pl_surround.databuf;
- ao_plugin_data.len=samples*sizeof(int16_t)*4;
+ ao_plugin_data.len=samples*sizeof(int16_t)*pl_surround.output_channels;
return 1;
}
? libavcodec/.depend
? libavcodec/README.MPlayer
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