Utility functions (CRC calc & float->int converters)

[imported from MPlayer, based on a52dec's libao]

Originally committed as revision 1780 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 183 insertions, 0 deletions

diff --git a/libavcodec/liba52/resample_c.c b/libavcodec/liba52/resample_c.c
new file mode 100644
index 0000000000..a618ec6e9e
--- /dev/null
+++ b/libavcodec/liba52/resample_c.c
@@ -0,0 +1,183 @@
+// this code is based on a52dec/libao/audio_out_oss.c
+
+static inline int16_t convert (int32_t i)
+{
+    if (i > 0x43c07fff)
+	return 32767;
+    else if (i < 0x43bf8000)
+	return -32768;
+    else
+	return i - 0x43c00000;
+}
+
+static int a52_resample_MONO_to_5_C(float * _f, int16_t * s16){
+    int i;
+    int32_t * f = (int32_t *) _f;
+	for (i = 0; i < 256; i++) {
+	    s16[5*i] = s16[5*i+1] = s16[5*i+2] = s16[5*i+3] = 0;
+	    s16[5*i+4] = convert (f[i]);
+	}
+    return 5*256;
+}
+
+static int a52_resample_MONO_to_1_C(float * _f, int16_t * s16){
+    int i;
+    int32_t * f = (int32_t *) _f;
+	for (i = 0; i < 256; i++) {
+	    s16[i] = convert (f[i]);
+	}
+    return 1*256;
+}
+
+static int a52_resample_STEREO_to_2_C(float * _f, int16_t * s16){
+    int i;
+    int32_t * f = (int32_t *) _f;
+	for (i = 0; i < 256; i++) {
+	    s16[2*i] = convert (f[i]);
+	    s16[2*i+1] = convert (f[i+256]);
+	}
+    return 2*256;
+}
+
+static int a52_resample_3F_to_5_C(float * _f, int16_t * s16){
+    int i;
+    int32_t * f = (int32_t *) _f;
+	for (i = 0; i < 256; i++) {
+	    s16[5*i] = convert (f[i]);
+	    s16[5*i+1] = convert (f[i+512]);
+	    s16[5*i+2] = s16[5*i+3] = 0;
+	    s16[5*i+4] = convert (f[i+256]);
+	}
+    return 5*256;
+}
+
+static int a52_resample_2F_2R_to_4_C(float * _f, int16_t * s16){
+    int i;
+    int32_t * f = (int32_t *) _f;
+	for (i = 0; i < 256; i++) {
+	    s16[4*i] = convert (f[i]);
+	    s16[4*i+1] = convert (f[i+256]);
+	    s16[4*i+2] = convert (f[i+512]);
+	    s16[4*i+3] = convert (f[i+768]);
+	}
+    return 4*256;
+}
+
+static int a52_resample_3F_2R_to_5_C(float * _f, int16_t * s16){
+    int i;
+    int32_t * f = (int32_t *) _f;
+	for (i = 0; i < 256; i++) {
+	    s16[5*i] = convert (f[i]);
+	    s16[5*i+1] = convert (f[i+512]);
+	    s16[5*i+2] = convert (f[i+768]);
+	    s16[5*i+3] = convert (f[i+1024]);
+	    s16[5*i+4] = convert (f[i+256]);
+	}
+    return 5*256;
+}
+
+static int a52_resample_MONO_LFE_to_6_C(float * _f, int16_t * s16){
+    int i;
+    int32_t * f = (int32_t *) _f;
+	for (i = 0; i < 256; i++) {
+	    s16[6*i] = s16[6*i+1] = s16[6*i+2] = s16[6*i+3] = 0;
+	    s16[6*i+4] = convert (f[i+256]);
+	    s16[6*i+5] = convert (f[i]);
+	}
+    return 6*256;
+}
+
+static int a52_resample_STEREO_LFE_to_6_C(float * _f, int16_t * s16){
+    int i;
+    int32_t * f = (int32_t *) _f;
+	for (i = 0; i < 256; i++) {
+	    s16[6*i] = convert (f[i+256]);
+	    s16[6*i+1] = convert (f[i+512]);
+	    s16[6*i+2] = s16[6*i+3] = s16[6*i+4] = 0;
+	    s16[6*i+5] = convert (f[i]);
+	}
+    return 6*256;
+}
+
+static int a52_resample_3F_LFE_to_6_C(float * _f, int16_t * s16){
+    int i;
+    int32_t * f = (int32_t *) _f;
+	for (i = 0; i < 256; i++) {
+	    s16[6*i] = convert (f[i+256]);
+	    s16[6*i+1] = convert (f[i+768]);
+	    s16[6*i+2] = s16[6*i+3] = 0;
+	    s16[6*i+4] = convert (f[i+512]);
+	    s16[6*i+5] = convert (f[i]);
+	}
+    return 6*256;
+}
+
+static int a52_resample_2F_2R_LFE_to_6_C(float * _f, int16_t * s16){
+    int i;
+    int32_t * f = (int32_t *) _f;
+	for (i = 0; i < 256; i++) {
+	    s16[6*i] = convert (f[i+256]);
+	    s16[6*i+1] = convert (f[i+512]);
+	    s16[6*i+2] = convert (f[i+768]);
+	    s16[6*i+3] = convert (f[i+1024]);
+	    s16[6*i+4] = 0;
+	    s16[6*i+5] = convert (f[i]);
+	}
+    return 6*256;
+}
+
+static int a52_resample_3F_2R_LFE_to_6_C(float * _f, int16_t * s16){
+    int i;
+    int32_t * f = (int32_t *) _f;
+	for (i = 0; i < 256; i++) {
+	    s16[6*i] = convert (f[i+256]);
+	    s16[6*i+1] = convert (f[i+768]);
+	    s16[6*i+2] = convert (f[i+1024]);
+	    s16[6*i+3] = convert (f[i+1280]);
+	    s16[6*i+4] = convert (f[i+512]);
+	    s16[6*i+5] = convert (f[i]);
+	}
+    return 6*256;
+}
+
+
+static void* a52_resample_C(int flags, int ch){
+    switch (flags) {
+    case A52_MONO:
+	if(ch==5) return a52_resample_MONO_to_5_C;
+	if(ch==1) return a52_resample_MONO_to_1_C;
+	break;
+    case A52_CHANNEL:
+    case A52_STEREO:
+    case A52_DOLBY:
+	if(ch==2) return a52_resample_STEREO_to_2_C;
+	break;
+    case A52_3F:
+	if(ch==5) return a52_resample_3F_to_5_C;
+	break;
+    case A52_2F2R:
+	if(ch==4) return a52_resample_2F_2R_to_4_C;
+	break;
+    case A52_3F2R:
+	if(ch==5) return a52_resample_3F_2R_to_5_C;
+	break;
+    case A52_MONO | A52_LFE:
+	if(ch==6) return a52_resample_MONO_LFE_to_6_C;
+	break;
+    case A52_CHANNEL | A52_LFE:
+    case A52_STEREO | A52_LFE:
+    case A52_DOLBY | A52_LFE:
+	if(ch==6) return a52_resample_STEREO_LFE_to_6_C;
+	break;
+    case A52_3F | A52_LFE:
+	if(ch==6) return a52_resample_3F_LFE_to_6_C;
+	break;
+    case A52_2F2R | A52_LFE:
+	if(ch==6) return a52_resample_2F_2R_LFE_to_6_C;
+	break;
+    case A52_3F2R | A52_LFE:
+	if(ch==6) return a52_resample_3F_2R_LFE_to_6_C;
+	break;
+    }
+    return NULL;
+}