matroskadec: export full wavpack blocks.

This allows us to get rid of demuxer-specific hacks in the decoder and
will allow streamcopy from matroska once we have a wavpack muxer.

1 files changed, 98 insertions, 0 deletions

diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 3b801e0845..d88b34fef7 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -1929,6 +1929,88 @@ static int matroska_parse_rm_audio(MatroskaDemuxContext *matroska,
 
     return 0;
 }
+
+/* reconstruct full wavpack blocks from mangled matroska ones */
+static int matroska_parse_wavpack(MatroskaTrack *track, uint8_t *src,
+                                  uint8_t **pdst, int *size)
+{
+    uint8_t *dst = NULL;
+    int dstlen   = 0;
+    int srclen   = *size;
+    uint32_t samples;
+    uint16_t ver;
+    int ret, offset = 0;
+
+    if (srclen < 12 || track->stream->codec->extradata_size < 2)
+        return AVERROR_INVALIDDATA;
+
+    ver = AV_RL16(track->stream->codec->extradata);
+
+    samples = AV_RL32(src);
+    src    += 4;
+    srclen -= 4;
+
+    while (srclen >= 8) {
+        int multiblock;
+        uint32_t blocksize;
+        uint8_t *tmp;
+
+        uint32_t flags = AV_RL32(src);
+        uint32_t crc   = AV_RL32(src + 4);
+        src    += 8;
+        srclen -= 8;
+
+        multiblock = (flags & 0x1800) != 0x1800;
+        if (multiblock) {
+            if (srclen < 4) {
+                ret = AVERROR_INVALIDDATA;
+                goto fail;
+            }
+            blocksize = AV_RL32(src);
+            src    += 4;
+            srclen -= 4;
+        } else
+            blocksize = srclen;
+
+        if (blocksize > srclen) {
+            ret = AVERROR_INVALIDDATA;
+            goto fail;
+        }
+
+        tmp = av_realloc(dst, dstlen + blocksize + 32);
+        if (!tmp) {
+            ret = AVERROR(ENOMEM);
+            goto fail;
+        }
+        dst     = tmp;
+        dstlen += blocksize + 32;
+
+        AV_WL32(dst + offset,      MKTAG('w', 'v', 'p', 'k')); // tag
+        AV_WL32(dst + offset + 4,  blocksize + 24);            // blocksize - 8
+        AV_WL16(dst + offset + 8,  ver);                       // version
+        AV_WL16(dst + offset + 10, 0);                         // track/index_no
+        AV_WL32(dst + offset + 12, 0);                         // total samples
+        AV_WL32(dst + offset + 16, 0);                         // block index
+        AV_WL32(dst + offset + 20, samples);                   // number of samples
+        AV_WL32(dst + offset + 24, flags);                     // flags
+        AV_WL32(dst + offset + 28, crc);                       // crc
+        memcpy (dst + offset + 32, src, blocksize);            // block data
+
+        src    += blocksize;
+        srclen -= blocksize;
+        offset += blocksize + 32;
+    }
+
+    *pdst = dst;
+    *size = dstlen;
+
+    return 0;
+
+fail:
+    av_freep(&dst);
+    return ret;
+}
+
 static int matroska_parse_frame(MatroskaDemuxContext *matroska,
                                 MatroskaTrack *track,
                                 AVStream *st,
@@ -1947,6 +2029,18 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska,
             return res;
     }
 
+    if (st->codec->codec_id == AV_CODEC_ID_WAVPACK) {
+        uint8_t *wv_data;
+        res = matroska_parse_wavpack(track, pkt_data, &wv_data, &pkt_size);
+        if (res < 0) {
+            av_log(matroska->ctx, AV_LOG_ERROR, "Error parsing a wavpack block.\n");
+            goto fail;
+        }
+        if (pkt_data != data)
+            av_freep(&pkt_data);
+        pkt_data = wv_data;
+    }
+
     if (st->codec->codec_id == AV_CODEC_ID_PRORES)
         offset = 8;
 
@@ -1996,6 +2090,10 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska,
     }
 
     return 0;
+fail:
+    if (pkt_data != data)
+        av_freep(&pkt_data);
+    return res;
 }
 
 static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,