avformat: Use G726LE decoder for Sun AU files

fixes ticket #1955 as suggested by Roman.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/au.c

@@ -45,8 +45,12 @@ static const AVCodecTag codec_au_tags[] = {
     { AV_CODEC_ID_PCM_S32BE,  5 },
     { AV_CODEC_ID_PCM_F32BE,  6 },
     { AV_CODEC_ID_PCM_F64BE,  7 },
+    { AV_CODEC_ID_ADPCM_G726LE, 23 },
     { AV_CODEC_ID_ADPCM_G722,24 },
+    { AV_CODEC_ID_ADPCM_G726LE, 25 },
+    { AV_CODEC_ID_ADPCM_G726LE, 26 },
     { AV_CODEC_ID_PCM_ALAW,  27 },
+    { AV_CODEC_ID_ADPCM_G726LE, MKBETAG('7','2','6','2') },
     { AV_CODEC_ID_NONE,       0 },
 };
 
@@ -101,7 +105,14 @@ static int au_read_header(AVFormatContext *s)
     }
 
     bps = av_get_bits_per_sample(codec);
-    if (!bps) {
+    if (codec == AV_CODEC_ID_ADPCM_G726LE) {
+        if (id == MKBETAG('7','2','6','2')) {
+            bps = 2;
+        } else {
+            const uint8_t bpcss[] = {4, 0, 3, 5};
+            bps = bpcss[id - 23];
+        }
+    } else if (!bps) {
         avpriv_request_sample(s, "Unknown bits per sample");
         return AVERROR_PATCHWELCOME;
     }
@@ -124,6 +135,7 @@ static int au_read_header(AVFormatContext *s)
     st->codec->codec_id    = codec;
     st->codec->channels    = channels;
     st->codec->sample_rate = rate;
+    st->codec->bits_per_coded_sample = bps;
     st->codec->bit_rate    = channels * rate * bps;
     st->codec->block_align = FFMAX(bps * st->codec->channels / 8, 1);
     if (data_size != AU_UNKNOWN_SIZE)