Make some functions static

These functions are not used outside their respective files, and they
lack a prototype in a header.

Originally committed as revision 22259 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/atrac1.c

@@ -252,7 +252,7 @@ static int at1_unpack_dequant(GetBitContext* gb, AT1SUCtx* su,
 }
 
 
-void at1_subband_synthesis(AT1Ctx *q, AT1SUCtx* su, float *pOut)
+static void at1_subband_synthesis(AT1Ctx *q, AT1SUCtx* su, float *pOut)
 {
     float temp[256];
     float iqmf_temp[512 + 46];

libavcodec/mpegaudiodec.c

@@ -101,7 +101,7 @@ DECLARE_ALIGNED(16, MPA_INT, ff_mpa_synth_window)[512];
  * Convert region offsets to region sizes and truncate
  * size to big_values.
  */
-void ff_region_offset2size(GranuleDef *g){
+static void ff_region_offset2size(GranuleDef *g){
     int i, k, j=0;
     g->region_size[2] = (576 / 2);
     for(i=0;i<3;i++) {
@@ -111,7 +111,7 @@ void ff_region_offset2size(GranuleDef *g){
     }
 }
 
-void ff_init_short_region(MPADecodeContext *s, GranuleDef *g){
+static void ff_init_short_region(MPADecodeContext *s, GranuleDef *g){
     if (g->block_type == 2)
         g->region_size[0] = (36 / 2);
     else {
@@ -125,7 +125,7 @@ void ff_init_short_region(MPADecodeContext *s, GranuleDef *g){
     g->region_size[1] = (576 / 2);
 }
 
-void ff_init_long_region(MPADecodeContext *s, GranuleDef *g, int ra1, int ra2){
+static void ff_init_long_region(MPADecodeContext *s, GranuleDef *g, int ra1, int ra2){
     int l;
     g->region_size[0] =
         band_index_long[s->sample_rate_index][ra1 + 1] >> 1;
@@ -135,7 +135,7 @@ void ff_init_long_region(MPADecodeContext *s, GranuleDef *g, int ra1, int ra2){
         band_index_long[s->sample_rate_index][l] >> 1;
 }
 
-void ff_compute_band_indexes(MPADecodeContext *s, GranuleDef *g){
+static void ff_compute_band_indexes(MPADecodeContext *s, GranuleDef *g){
     if (g->block_type == 2) {
         if (g->switch_point) {
             /* if switched mode, we handle the 36 first samples as

libavcodec/rdft.c

@@ -80,7 +80,7 @@ av_cold int ff_rdft_init(RDFTContext *s, int nbits, enum RDFTransformType trans)
  * the two real FFTs into one complex FFT. Unmangle the results.
  * ref: http://www.engineeringproductivitytools.com/stuff/T0001/PT10.HTM
  */
-void ff_rdft_calc_c(RDFTContext* s, FFTSample* data)
+static void ff_rdft_calc_c(RDFTContext* s, FFTSample* data)
 {
     int i, i1, i2;
     FFTComplex ev, od;