Handle more ADPCM codecs in av_get_bits_per_sample().

This removes some special-case code from riff.c.
CODEC_ID_ADPCM_G726 is still handled in riff.c as before because it is
not guaranteed to be fixed 4 bits per sample.

Originally committed as revision 21037 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/utils.c

@@ -963,6 +963,9 @@ int av_get_bits_per_sample(enum CodecID codec_id){
         return 3;
     case CODEC_ID_ADPCM_SBPRO_4:
     case CODEC_ID_ADPCM_CT:
+    case CODEC_ID_ADPCM_WAV:
+    case CODEC_ID_ADPCM_MS:
+    case CODEC_ID_ADPCM_YAMAHA:
         return 4;
     case CODEC_ID_PCM_ALAW:
     case CODEC_ID_PCM_MULAW:

libavformat/riff.c

@@ -336,7 +336,7 @@ int ff_put_wav_header(ByteIOContext *pb, AVCodecContext *enc)
     put_le32(pb, enc->sample_rate);
     if (enc->codec_id == CODEC_ID_MP2 || enc->codec_id == CODEC_ID_MP3 || enc->codec_id == CODEC_ID_GSM_MS) {
         bps = 0;
-    } else if (enc->codec_id == CODEC_ID_ADPCM_IMA_WAV || enc->codec_id == CODEC_ID_ADPCM_MS || enc->codec_id == CODEC_ID_ADPCM_G726 || enc->codec_id == CODEC_ID_ADPCM_YAMAHA) { //
+    } else if (enc->codec_id == CODEC_ID_ADPCM_G726) {
         bps = 4;
     } else {
         if (!(bps = av_get_bits_per_sample(enc->codec_id)))