user selectble cutoff frequency

Originally committed as revision 3619 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/avcodec.h

@@ -17,7 +17,7 @@ extern "C" {
 
 #define FFMPEG_VERSION_INT     0x000409
 #define FFMPEG_VERSION         "0.4.9-pre1"
-#define LIBAVCODEC_BUILD       4726
+#define LIBAVCODEC_BUILD       4727
 
 #define LIBAVCODEC_VERSION_INT FFMPEG_VERSION_INT
 #define LIBAVCODEC_VERSION     FFMPEG_VERSION
@@ -1942,7 +1942,7 @@ ReSampleContext *audio_resample_init(int output_channels, int input_channels,
 int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
 void audio_resample_close(ReSampleContext *s);
 
-struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear);
+struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
 int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
 void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
 void av_resample_close(struct AVResampleContext *c);

libavcodec/resample.c

@@ -160,7 +160,7 @@ ReSampleContext *audio_resample_init(int output_channels, int input_channels,
     if(s->filter_channels>2)
       s->filter_channels = 2;
 
-    s->resample_context= av_resample_init(output_rate, input_rate, 16, 10, 0);
+    s->resample_context= av_resample_init(output_rate, input_rate, 16, 10, 0, 1.0);
     
     return s;
 }

libavcodec/resample2.c

@@ -130,9 +130,9 @@ void av_build_filter(FELEM *filter, double factor, int tap_count, int phase_coun
  * initalizes a audio resampler.
  * note, if either rate is not a integer then simply scale both rates up so they are
  */
-AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_size, int phase_shift, int linear){
+AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_size, int phase_shift, int linear, double cutoff){
     AVResampleContext *c= av_mallocz(sizeof(AVResampleContext));
-    double factor= FFMIN(out_rate / (double)in_rate, 1.0);
+    double factor= FFMIN(out_rate * cutoff / in_rate, 1.0);
     int phase_count= 1<<phase_shift;
     
     memset(c, 0, sizeof(AVResampleContext));