[libav-devel] [PATCH] Musepack SV7: try to read files without number of frames provided

[Kostya Shishkov]

---
 libavformat/mpc.c |   26 +++++++++++++++++++++++---
 1 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/libavformat/mpc.c b/libavformat/mpc.c
index 0aec1e8..ea6c90f 100644
--- a/libavformat/mpc.c
+++ b/libavformat/mpc.c
@@ -41,6 +41,7 @@ typedef struct {
     MPCFrame *frames;
     int curbits;
     int frames_noted;
+    int unknown_num_frames;
 } MPCContext;
 
 static int mpc_probe(AVProbeData *p)
@@ -70,6 +71,13 @@ static int mpc_read_header(AVFormatContext *s, 
AVFormatParameters *ap)
         av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
         return -1;
     }
+    if(c->fcount){
+        c->unknown_num_frames = 0;
+    }else{
+        c->unknown_num_frames = 1;
+        c->fcount             = 1;
+        av_log(s, AV_LOG_WARNING, "Container reports no frames\n");
+    }
     c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
     c->curframe = 0;
     c->lastframe = -1;
@@ -91,7 +99,8 @@ static int mpc_read_header(AVFormatContext *s, 
AVFormatParameters *ap)
     av_set_pts_info(st, 32, MPC_FRAMESIZE, st->codec->sample_rate);
     /* scan for seekpoints */
     st->start_time = 0;
-    st->duration = c->fcount;
+    if(!c->unknown_num_frames)
+        st->duration = c->fcount;
 
     /* try to read APE tags */
     if (s->pb->seekable) {
@@ -111,7 +120,7 @@ static int mpc_read_packet(AVFormatContext *s, AVPacket 
*pkt)
     int ret, size, size2, curbits, cur = c->curframe;
     int64_t tmp, pos;
 
-    if (c->curframe >= c->fcount)
+    if (c->curframe >= c->fcount && !c->unknown_num_frames)
         return -1;
 
     if(c->curframe != c->lastframe + 1){
@@ -134,6 +143,17 @@ static int mpc_read_packet(AVFormatContext *s, AVPacket 
*pkt)
 
     size = ((size2 + curbits + 31) & ~31) >> 3;
     if(cur == c->frames_noted){
+        if(c->unknown_num_frames){
+            if(((int64_t)cur + 1) * sizeof(MPCFrame) >= UINT_MAX){
+                av_log(s, AV_LOG_ERROR, "Too many frames encountered\n");
+                return AVERROR(ENOMEM);
+            }
+            c->frames = av_realloc(c->frames, (cur + 1) * sizeof(MPCFrame));
+            if(!c->frames){
+                av_log(s, AV_LOG_ERROR, "Cannot grow seektable\n");
+                return AVERROR(ENOMEM);
+            }
+        }
         c->frames[cur].pos = pos;
         c->frames[cur].size = size;
         c->frames[cur].skip = curbits - 20;
@@ -146,7 +166,7 @@ static int mpc_read_packet(AVFormatContext *s, AVPacket 
*pkt)
         return AVERROR(EIO);
 
     pkt->data[0] = curbits;
-    pkt->data[1] = (c->curframe > c->fcount);
+    pkt->data[1] = (c->curframe > c->fcount) && !c->unknown_num_frames;
     pkt->data[2] = 0;
     pkt->data[3] = 0;
 
-- 
1.7.0.4

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