Document ff_des_encdec

[ffmpeg] / libavcodec / dpcm.c

diff --git a/libavcodec/dpcm.c b/libavcodec/dpcm.c
index df9da948966fe1654e9bfec7ab7b719179402f0f..c4a127d7c71b71f8357c8ab5371c6efcd295eda0 100644 (file)
--- a/libavcodec/dpcm.c
+++ b/libavcodec/dpcm.c
@@ -2,18 +2,20 @@
  * Assorted DPCM codecs
  * Copyright (c) 2003 The ffmpeg Project.
  *
- * This library is free software; you can redistribute it and/or
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
  *
- * This library is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
@@ -44,8 +46,6 @@ typedef struct DPCMContext {
     const int *sol_table;//for SOL_DPCM
 } DPCMContext;
 
-#define SATURATE_S16(x)  if (x < -32768) x = -32768; \
-  else if (x > 32767) x = 32767;
 #define SE_16BIT(x)  if (x & 0x8000) x -= 0x10000;
 
 static int interplay_delta_table[] = {
@@ -173,11 +173,15 @@ static int dpcm_decode_frame(AVCodecContext *avctx,
     if (!buf_size)
         return 0;
 
+    // almost every DPCM variant expands one byte of data into two
+    if(*data_size/2 < buf_size)
+        return -1;
+
     switch(avctx->codec->id) {
 
     case CODEC_ID_ROQ_DPCM:
         if (s->channels == 1)
-            predictor[0] = LE_16(&buf[6]);
+            predictor[0] = AV_RL16(&buf[6]);
         else {
             predictor[0] = buf[7] << 8;
             predictor[1] = buf[6] << 8;
@@ -188,7 +192,7 @@ static int dpcm_decode_frame(AVCodecContext *avctx,
         /* decode the samples */
         for (in = 8, out = 0; in < buf_size; in++, out++) {
             predictor[channel_number] += s->roq_square_array[buf[in]];
-            SATURATE_S16(predictor[channel_number]);
+            predictor[channel_number] = av_clip_int16(predictor[channel_number]);
             output_samples[out] = predictor[channel_number];
 
             /* toggle channel */
@@ -198,12 +202,12 @@ static int dpcm_decode_frame(AVCodecContext *avctx,
 
     case CODEC_ID_INTERPLAY_DPCM:
         in = 6;  /* skip over the stream mask and stream length */
-        predictor[0] = LE_16(&buf[in]);
+        predictor[0] = AV_RL16(&buf[in]);
         in += 2;
         SE_16BIT(predictor[0])
         output_samples[out++] = predictor[0];
         if (s->channels == 2) {
-            predictor[1] = LE_16(&buf[in]);
+            predictor[1] = AV_RL16(&buf[in]);
             in += 2;
             SE_16BIT(predictor[1])
             output_samples[out++] = predictor[1];
@@ -211,7 +215,7 @@ static int dpcm_decode_frame(AVCodecContext *avctx,
 
         while (in < buf_size) {
             predictor[channel_number] += interplay_delta_table[buf[in++]];
-            SATURATE_S16(predictor[channel_number]);
+            predictor[channel_number] = av_clip_int16(predictor[channel_number]);
             output_samples[out++] = predictor[channel_number];
 
             /* toggle channel */
@@ -223,11 +227,11 @@ static int dpcm_decode_frame(AVCodecContext *avctx,
     case CODEC_ID_XAN_DPCM:
         in = 0;
         shift[0] = shift[1] = 4;
-        predictor[0] = LE_16(&buf[in]);
+        predictor[0] = AV_RL16(&buf[in]);
         in += 2;
         SE_16BIT(predictor[0]);
         if (s->channels == 2) {
-            predictor[1] = LE_16(&buf[in]);
+            predictor[1] = AV_RL16(&buf[in]);
             in += 2;
             SE_16BIT(predictor[1]);
         }
@@ -246,7 +250,7 @@ static int dpcm_decode_frame(AVCodecContext *avctx,
             diff >>= shift[channel_number];
             predictor[channel_number] += diff;
 
-            SATURATE_S16(predictor[channel_number]);
+            predictor[channel_number] = av_clip_int16(predictor[channel_number]);
             output_samples[out++] = predictor[channel_number];
 
             /* toggle channel */
@@ -256,6 +260,8 @@ static int dpcm_decode_frame(AVCodecContext *avctx,
     case CODEC_ID_SOL_DPCM:
         in = 0;
         if (avctx->codec_tag != 3) {
+            if(*data_size/4 < buf_size)
+                return -1;
             while (in < buf_size) {
                 int n1, n2;
                 n1 = (buf[in] >> 4) & 0xF;
@@ -275,7 +281,7 @@ static int dpcm_decode_frame(AVCodecContext *avctx,
                 n = buf[in++];
                 if (n & 0x80) s->sample[channel_number] -= s->sol_table[n & 0x7F];
                 else s->sample[channel_number] += s->sol_table[n & 0x7F];
-                SATURATE_S16(s->sample[channel_number]);
+                s->sample[channel_number] = av_clip_int16(s->sample[channel_number]);
                 output_samples[out++] = s->sample[channel_number];
                 /* toggle channel */
                 channel_number ^= s->channels - 1;