Add a av_fast_malloc function and replace several uses of av_fast_realloc,

thus avoiding potential memleaks and pointless memcpys.

Originally committed as revision 18470 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/4xm.c

@@ -378,7 +378,9 @@ static int decode_p_frame(FourXContext *f, const uint8_t *buf, int length){
         return -1;
     }
 
-    f->bitstream_buffer= av_fast_realloc(f->bitstream_buffer, &f->bitstream_buffer_size, bitstream_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    av_fast_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size, bitstream_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    if (!f->bitstream_buffer)
+        return AVERROR(ENOMEM);
     f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)(buf + extra), bitstream_size/4);
     init_get_bits(&f->gb, f->bitstream_buffer, 8*bitstream_size);
 
@@ -656,7 +658,9 @@ static int decode_i_frame(FourXContext *f, const uint8_t *buf, int length){
 
     prestream_size= length + buf - prestream;
 
-    f->bitstream_buffer= av_fast_realloc(f->bitstream_buffer, &f->bitstream_buffer_size, prestream_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    av_fast_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size, prestream_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    if (!f->bitstream_buffer)
+        return AVERROR(ENOMEM);
     f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)prestream, prestream_size/4);
     init_get_bits(&f->pre_gb, f->bitstream_buffer, 8*prestream_size);
 

libavcodec/asv1.c

@@ -408,7 +408,9 @@ static int decode_frame(AVCodecContext *avctx,
     p->pict_type= FF_I_TYPE;
     p->key_frame= 1;
 
-    a->bitstream_buffer= av_fast_realloc(a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    av_fast_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    if (!a->bitstream_buffer)
+        return AVERROR(ENOMEM);
 
     if(avctx->codec_id == CODEC_ID_ASV1)
         a->dsp.bswap_buf((uint32_t*)a->bitstream_buffer, (const uint32_t*)buf, buf_size/4);

libavcodec/avcodec.h

@@ -3540,6 +3540,20 @@ AVBitStreamFilter *av_bitstream_filter_next(AVBitStreamFilter *f);
  */
 void *av_fast_realloc(void *ptr, unsigned int *size, unsigned int min_size);
 
+/**
+ * Allocates a buffer, reusing the given one if large enough.
+ *
+ * Contrary to av_fast_realloc the current buffer contents might not be
+ * preserved and on error the old buffer is freed, thus no special
+ * handling to avoid memleaks is necessary.
+ *
+ * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer
+ * @param size size of the buffer *ptr points to
+ * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and
+ *                 *size 0 if an error occurred.
+ */
+void av_fast_malloc(void *ptr, unsigned int *size, unsigned int min_size);
+
 /**
  * Copy image 'src' to 'dst'.
  */

libavcodec/eatqi.c

@@ -126,7 +126,7 @@ static int tqi_decode_frame(AVCodecContext *avctx,
         return -1;
     }
 
-    t->bitstream_buf = av_fast_realloc(t->bitstream_buf, &t->bitstream_buf_size, (buf_end-buf) + FF_INPUT_BUFFER_PADDING_SIZE);
+    av_fast_malloc(&t->bitstream_buf, &t->bitstream_buf_size, (buf_end-buf) + FF_INPUT_BUFFER_PADDING_SIZE);
     if (!t->bitstream_buf)
         return AVERROR(ENOMEM);
     s->dsp.bswap_buf(t->bitstream_buf, (const uint32_t*)buf, (buf_end-buf)/4);

libavcodec/h263dec.c

@@ -687,10 +687,12 @@ retry:
         }
 
         if(startcode_found){
-            s->bitstream_buffer= av_fast_realloc(
-                s->bitstream_buffer,
+            av_fast_malloc(
+                &s->bitstream_buffer,
                 &s->allocated_bitstream_buffer_size,
                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
+            if (!s->bitstream_buffer)
+                return AVERROR(ENOMEM);
             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
             s->bitstream_buffer_size= buf_size - current_pos;
         }

libavcodec/h264.c

@@ -1411,7 +1411,7 @@ const uint8_t *ff_h264_decode_nal(H264Context *h, const uint8_t *src, int *dst_l
     }
 
     bufidx = h->nal_unit_type == NAL_DPC ? 1 : 0; // use second escape buffer for inter data
-    h->rbsp_buffer[bufidx]= av_fast_realloc(h->rbsp_buffer[bufidx], &h->rbsp_buffer_size[bufidx], length+FF_INPUT_BUFFER_PADDING_SIZE);
+    av_fast_malloc(&h->rbsp_buffer[bufidx], &h->rbsp_buffer_size[bufidx], length+FF_INPUT_BUFFER_PADDING_SIZE);
     dst= h->rbsp_buffer[bufidx];
 
     if (dst == NULL){

libavcodec/huffyuv.c

@@ -956,7 +956,9 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPac
 
     AVFrame *picture = data;
 
-    s->bitstream_buffer= av_fast_realloc(s->bitstream_buffer, &s->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    av_fast_malloc(&s->bitstream_buffer, &s->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    if (!s->bitstream_buffer)
+        return AVERROR(ENOMEM);
 
     s->dsp.bswap_buf((uint32_t*)s->bitstream_buffer, (const uint32_t*)buf, buf_size/4);
 

libavcodec/mdec.c

@@ -174,7 +174,9 @@ static int decode_frame(AVCodecContext *avctx,
     p->pict_type= FF_I_TYPE;
     p->key_frame= 1;
 
-    a->bitstream_buffer= av_fast_realloc(a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    av_fast_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    if (!a->bitstream_buffer)
+        return AVERROR(ENOMEM);
     for(i=0; i<buf_size; i+=2){
         a->bitstream_buffer[i]  = buf[i+1];
         a->bitstream_buffer[i+1]= buf[i  ];

libavcodec/mimic.c

@@ -334,7 +334,7 @@ static int mimic_decode_frame(AVCodecContext *avctx, void *data,
     prepare_avpic(ctx, &ctx->flipped_ptrs[ctx->cur_index],
                   (AVPicture*) &ctx->buf_ptrs[ctx->cur_index]);
 
-    ctx->swap_buf = av_fast_realloc(ctx->swap_buf, &ctx->swap_buf_size,
+    av_fast_malloc(&ctx->swap_buf, &ctx->swap_buf_size,
                                  swap_buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
     if(!ctx->swap_buf)
         return AVERROR(ENOMEM);

libavcodec/motionpixels.c

@@ -297,7 +297,9 @@ static int mp_decode_frame(AVCodecContext *avctx,
     }
 
     /* le32 bitstream msb first */
-    mp->bswapbuf = av_fast_realloc(mp->bswapbuf, &mp->bswapbuf_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    av_fast_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    if (!mp->bswapbuf)
+        AVERROR(ENOMEM);
     mp->dsp.bswap_buf((uint32_t *)mp->bswapbuf, (const uint32_t *)buf, buf_size / 4);
     if (buf_size & 3)
         memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);

libavcodec/utils.c

@@ -80,6 +80,17 @@ void *av_fast_realloc(void *ptr, unsigned int *size, unsigned int min_size)
     return ptr;
 }
 
+void av_fast_malloc(void *ptr, unsigned int *size, unsigned int min_size)
+{
+    void **p = ptr;
+    if (min_size < *size)
+        return;
+    *size= FFMAX(17*min_size/16 + 32, min_size);
+    av_free(*p);
+    *p = av_malloc(*size);
+    if (!*p) *size = 0;
+}
+
 /* encoder management */
 static AVCodec *first_avcodec = NULL;