samplefmt: add av_get_bytes_per_sample()

Deprecate av_get_bits_per_sample_fmt(), which was a misnamed function.

For the moment we don't have sample formats with a non-integer number
of bytes, in that case we may need to create a new
av_get_bits_per_sample() function. In the meanwhile we prefer to adopt
this variant, since avoids divisions by 8 all over the place.

libavutil/samplefmt.c

@@ -66,8 +66,16 @@ char *av_get_sample_fmt_string (char *buf, int buf_size, enum AVSampleFormat sam
     return buf;
 }
 
+int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt)
+{
+     return sample_fmt < 0 || sample_fmt >= AV_SAMPLE_FMT_NB ?
+        0 : sample_fmt_info[sample_fmt].bits >> 3;
+}
+
+#if FF_API_GET_BITS_PER_SAMPLE_FMT
 int av_get_bits_per_sample_fmt(enum AVSampleFormat sample_fmt)
 {
     return sample_fmt < 0 || sample_fmt >= AV_SAMPLE_FMT_NB ?
         0 : sample_fmt_info[sample_fmt].bits;
 }
+#endif