matroskadec: move buffer decoding code to a separate function

original patch by Evgeniy Stepanov  eugeni.stepanov _at_ gmail.com

Originally committed as revision 13891 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/matroskadec.c

@@ -972,6 +972,82 @@ matroska_parse_info (MatroskaDemuxContext *matroska)
     return res;
 }
 
+static int
+matroska_decode_buffer(uint8_t** buf, int* buf_size, MatroskaTrack *track)
+{
+    uint8_t* data = *buf;
+    int isize = *buf_size;
+    uint8_t* pkt_data = NULL;
+    int pkt_size = isize;
+    int result = 0;
+    int olen;
+
+    switch (track->encoding_algo) {
+    case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
+        return track->encoding_settings_len;
+    case MATROSKA_TRACK_ENCODING_COMP_LZO:
+        do {
+            olen = pkt_size *= 3;
+            pkt_data = av_realloc(pkt_data,
+                                  pkt_size+LZO_OUTPUT_PADDING);
+            result = lzo1x_decode(pkt_data, &olen, data, &isize);
+        } while (result==LZO_OUTPUT_FULL && pkt_size<10000000);
+        if (result)
+            goto failed;
+        pkt_size -= olen;
+        break;
+#ifdef CONFIG_ZLIB
+    case MATROSKA_TRACK_ENCODING_COMP_ZLIB: {
+        z_stream zstream = {0};
+        if (inflateInit(&zstream) != Z_OK)
+            return -1;
+        zstream.next_in = data;
+        zstream.avail_in = isize;
+        do {
+            pkt_size *= 3;
+            pkt_data = av_realloc(pkt_data, pkt_size);
+            zstream.avail_out = pkt_size - zstream.total_out;
+            zstream.next_out = pkt_data + zstream.total_out;
+            result = inflate(&zstream, Z_NO_FLUSH);
+        } while (result==Z_OK && pkt_size<10000000);
+        pkt_size = zstream.total_out;
+        inflateEnd(&zstream);
+        if (result != Z_STREAM_END)
+            goto failed;
+        break;
+    }
+#endif
+#ifdef CONFIG_BZLIB
+    case MATROSKA_TRACK_ENCODING_COMP_BZLIB: {
+        bz_stream bzstream = {0};
+        if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
+            return -1;
+        bzstream.next_in = data;
+        bzstream.avail_in = isize;
+        do {
+            pkt_size *= 3;
+            pkt_data = av_realloc(pkt_data, pkt_size);
+            bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
+            bzstream.next_out = pkt_data + bzstream.total_out_lo32;
+            result = BZ2_bzDecompress(&bzstream);
+        } while (result==BZ_OK && pkt_size<10000000);
+        pkt_size = bzstream.total_out_lo32;
+        BZ2_bzDecompressEnd(&bzstream);
+        if (result != BZ_STREAM_END)
+            goto failed;
+        break;
+    }
+#endif
+    }
+
+    *buf = pkt_data;
+    *buf_size = pkt_size;
+    return 0;
+ failed:
+    av_free(pkt_data);
+    return -1;
+}
+
 static int
 matroska_add_stream (MatroskaDemuxContext *matroska)
 {
@@ -2801,79 +2877,15 @@ matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data, int size,
                     matroska_queue_packet(matroska, pkt);
                 }
             } else {
-                int result, offset = 0, ilen, olen, pkt_size = lace_size[n];
+                int offset = 0, pkt_size = lace_size[n];
                 uint8_t *pkt_data = data;
 
                 if (matroska->tracks[track]->encoding_scope & 1) {
-                    switch (matroska->tracks[track]->encoding_algo) {
+                    offset = matroska_decode_buffer(&pkt_data, &pkt_size,
-                    case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
+                                                    matroska->tracks[track]);
-                        offset = matroska->tracks[track]->encoding_settings_len;
+                    if (offset < 0)
-                        break;
-                    case MATROSKA_TRACK_ENCODING_COMP_LZO:
-                        pkt_data = NULL;
-                        do {
-                            ilen = lace_size[n];
-                            olen = pkt_size *= 3;
-                            pkt_data = av_realloc(pkt_data,
-                                                  pkt_size+LZO_OUTPUT_PADDING);
-                            result = lzo1x_decode(pkt_data, &olen, data, &ilen);
-                        } while (result==LZO_OUTPUT_FULL && pkt_size<10000000);
-                        if (result) {
-                            av_free(pkt_data);
                         continue;
                 }
-                        pkt_size -= olen;
-                        break;
-#ifdef CONFIG_ZLIB
-                    case MATROSKA_TRACK_ENCODING_COMP_ZLIB: {
-                        z_stream zstream = {0};
-                        pkt_data = NULL;
-                        if (inflateInit(&zstream) != Z_OK)
-                            continue;
-                        zstream.next_in = data;
-                        zstream.avail_in = lace_size[n];
-                        do {
-                            pkt_size *= 3;
-                            pkt_data = av_realloc(pkt_data, pkt_size);
-                            zstream.avail_out = pkt_size - zstream.total_out;
-                            zstream.next_out = pkt_data + zstream.total_out;
-                            result = inflate(&zstream, Z_NO_FLUSH);
-                        } while (result==Z_OK && pkt_size<10000000);
-                        pkt_size = zstream.total_out;
-                        inflateEnd(&zstream);
-                        if (result != Z_STREAM_END) {
-                            av_free(pkt_data);
-                            continue;
-                        }
-                        break;
-                    }
-#endif
-#ifdef CONFIG_BZLIB
-                    case MATROSKA_TRACK_ENCODING_COMP_BZLIB: {
-                        bz_stream bzstream = {0};
-                        pkt_data = NULL;
-                        if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
-                            continue;
-                        bzstream.next_in = data;
-                        bzstream.avail_in = lace_size[n];
-                        do {
-                            pkt_size *= 3;
-                            pkt_data = av_realloc(pkt_data, pkt_size);
-                            bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
-                            bzstream.next_out = pkt_data + bzstream.total_out_lo32;
-                            result = BZ2_bzDecompress(&bzstream);
-                        } while (result==BZ_OK && pkt_size<10000000);
-                        pkt_size = bzstream.total_out_lo32;
-                        BZ2_bzDecompressEnd(&bzstream);
-                        if (result != BZ_STREAM_END) {
-                            av_free(pkt_data);
-                            continue;
-                        }
-                        break;
-                    }
-#endif
-                    }
-                }
 
                 pkt = av_mallocz(sizeof(AVPacket));
                 /* XXX: prevent data copy... */