ws_snd: decode to AV_SAMPLE_FMT_U8 instead of S16.

8-bit unsigned is the native sample format.

libavcodec/ws-snd1.c

@@ -37,13 +37,11 @@ static const int8_t ws_adpcm_4bit[] = {
     -9, -8, -6, -5, -4, -3, -2, -1,
      0,  1,  2,  3,  4,  5,  6,  8 };
 
-#define CLIP8(a) if(a>127)a=127;if(a<-128)a=-128;
-
 static av_cold int ws_snd_decode_init(AVCodecContext * avctx)
 {
 //    WSSNDContext *c = avctx->priv_data;
 
-    avctx->sample_fmt = AV_SAMPLE_FMT_S16;
+    avctx->sample_fmt = AV_SAMPLE_FMT_U8;
     return 0;
 }
 
@@ -56,15 +54,14 @@ static int ws_snd_decode_frame(AVCodecContext *avctx,
 //    WSSNDContext *c = avctx->priv_data;
 
     int in_size, out_size;
-    int sample = 0;
+    int sample = 128;
     int i;
-    short *samples = data;
+    uint8_t *samples = data;
 
     if (!buf_size)
         return 0;
 
     out_size = AV_RL16(&buf[0]);
-    *data_size = out_size * 2;
     in_size = AV_RL16(&buf[2]);
     buf += 4;
 
@@ -76,9 +73,12 @@ static int ws_snd_decode_frame(AVCodecContext *avctx,
         av_log(avctx, AV_LOG_ERROR, "Frame data is larger than input buffer\n");
         return -1;
     }
+
+    *data_size = out_size;
+
     if (in_size == out_size) {
         for (i = 0; i < out_size; i++)
-            *samples++ = (*buf++ - 0x80) << 8;
+            *samples++ = *buf++;
         return buf_size;
     }
 
@@ -93,17 +93,17 @@ static int ws_snd_decode_frame(AVCodecContext *avctx,
             for (count++; count > 0; count--) {
                 code = *buf++;
                 sample += ws_adpcm_2bit[code & 0x3];
-                CLIP8(sample);
-                *samples++ = sample << 8;
+                sample = av_clip_uint8(sample);
+                *samples++ = sample;
                 sample += ws_adpcm_2bit[(code >> 2) & 0x3];
-                CLIP8(sample);
-                *samples++ = sample << 8;
+                sample = av_clip_uint8(sample);
+                *samples++ = sample;
                 sample += ws_adpcm_2bit[(code >> 4) & 0x3];
-                CLIP8(sample);
-                *samples++ = sample << 8;
+                sample = av_clip_uint8(sample);
+                *samples++ = sample;
                 sample += ws_adpcm_2bit[(code >> 6) & 0x3];
-                CLIP8(sample);
-                *samples++ = sample << 8;
+                sample = av_clip_uint8(sample);
+                *samples++ = sample;
                 out_size -= 4;
             }
             break;
@@ -111,11 +111,11 @@ static int ws_snd_decode_frame(AVCodecContext *avctx,
             for (count++; count > 0; count--) {
                 code = *buf++;
                 sample += ws_adpcm_4bit[code & 0xF];
-                CLIP8(sample);
-                *samples++ = sample << 8;
+                sample = av_clip_uint8(sample);
+                *samples++ = sample;
                 sample += ws_adpcm_4bit[code >> 4];
-                CLIP8(sample);
-                *samples++ = sample << 8;
+                sample = av_clip_uint8(sample);
+                *samples++ = sample;
                 out_size -= 2;
             }
             break;
@@ -125,19 +125,20 @@ static int ws_snd_decode_frame(AVCodecContext *avctx,
                 t = count;
                 t <<= 3;
                 sample += t >> 3;
-                *samples++ = sample << 8;
+                sample = av_clip_uint8(sample);
+                *samples++ = sample;
                 out_size--;
             } else { /* copy */
                 for (count++; count > 0; count--) {
-                    *samples++ = (*buf++ - 0x80) << 8;
+                    *samples++ = *buf++;
                     out_size--;
                 }
-                sample = buf[-1] - 0x80;
+                sample = buf[-1];
             }
             break;
         default: /* run */
             for(count++; count > 0; count--) {
-                *samples++ = sample << 8;
+                *samples++ = sample;
                 out_size--;
             }
         }