cleaned up buffer management

Originally committed as revision 5522 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/ogg2.c

@@ -193,8 +193,6 @@ ogg_new_stream (AVFormatContext * s, uint32_t serial)
     os = ogg->streams + idx;
     os->serial = serial;
     os->bufsize = DECODER_BUFFER_SIZE;
-    os->buf = av_malloc (os->bufsize);
-    memset (os->buf, 0, os->bufsize);
     os->header = -1;
 
     st = av_new_stream (s, idx);
@@ -207,6 +205,23 @@ ogg_new_stream (AVFormatContext * s, uint32_t serial)
     return idx;
 }
 
+static int
+ogg_new_buf(ogg_t *ogg, int idx)
+{
+    ogg_stream_t *os = ogg->streams + idx;
+    u_char *nb = av_malloc(os->bufsize);
+    int size = os->bufpos - os->pstart;
+    if(os->buf){
+        memcpy(nb, os->buf + os->pstart, size);
+        av_free(os->buf);
+    }
+    os->buf = nb;
+    os->bufpos = size;
+    os->pstart = 0;
+
+    return 0;
+}
+
 static int
 ogg_read_page (AVFormatContext * s, int *str)
 {
@@ -264,6 +279,9 @@ ogg_read_page (AVFormatContext * s, int *str)
 
     os = ogg->streams + idx;
 
+    if(os->segp == os->nsegs)
+        ogg_new_buf(ogg, idx);
+
     if (get_buffer (bc, os->segments, nsegs) < nsegs)
         return -1;
 
@@ -310,7 +328,7 @@ ogg_read_page (AVFormatContext * s, int *str)
 }
 
 static int
-ogg_packet (AVFormatContext * s, int *str)
+ogg_packet (AVFormatContext * s, int *str, int *dstart, int *dsize)
 {
     ogg_t *ogg = s->priv_data;
     int idx;
@@ -363,14 +381,6 @@ ogg_packet (AVFormatContext * s, int *str)
         }
 
         if (!complete && os->segp == os->nsegs){
-            uint8_t *nb = av_malloc (os->bufsize);
-            int size = os->bufpos - os->pstart;
-            memset (nb, 0, os->bufsize);
-            memcpy (nb, os->buf + os->pstart, size);
-            av_free (os->buf);
-            os->buf = nb;
-            os->bufpos = size;
-            os->pstart = 0;
             ogg->curidx = -1;
         }
     }while (!complete);
@@ -401,6 +411,12 @@ ogg_packet (AVFormatContext * s, int *str)
             os->codec->packet (s, idx);
         if (str)
             *str = idx;
+        if (dstart)
+            *dstart = os->pstart;
+        if (dsize)
+            *dsize = os->psize;
+        os->pstart += os->psize;
+        os->psize = 0;
     }
 
     os->seq++;
@@ -416,7 +432,7 @@ ogg_get_headers (AVFormatContext * s)
     ogg_t *ogg = s->priv_data;
 
     do{
-        if (ogg_packet (s, NULL) < 0)
+        if (ogg_packet (s, NULL, NULL, NULL) < 0)
             return -1;
     }while (!ogg->headers);
 
@@ -507,10 +523,11 @@ ogg_read_packet (AVFormatContext * s, AVPacket * pkt)
     ogg_t *ogg;
     ogg_stream_t *os;
     int idx = -1;
+    int pstart, psize;
 
     //Get an ogg packet
     do{
-        if (ogg_packet (s, &idx) < 0)
+        if (ogg_packet (s, &idx, &pstart, &psize) < 0)
             return AVERROR_IO;
     }while (idx < 0 || !s->streams[idx]);
 
@@ -518,18 +535,16 @@ ogg_read_packet (AVFormatContext * s, AVPacket * pkt)
     os = ogg->streams + idx;
 
     //Alloc a pkt
-    if (av_new_packet (pkt, os->psize) < 0)
+    if (av_new_packet (pkt, psize) < 0)
         return AVERROR_IO;
     pkt->stream_index = idx;
-    memcpy (pkt->data, os->buf + os->pstart, os->psize);
+    memcpy (pkt->data, os->buf + pstart, psize);
     if (os->lastgp != -1LL){
         pkt->pts = ogg_gptopts (s, idx, os->lastgp);
         os->lastgp = -1;
     }
-    //next
-    os->pstart += os->psize;
-    os->psize = 0;
-    return os->psize;
+
+    return psize;
 }