avformat/mpc: Simplify cleanup

Currently Musepack allocates an array that needs to be freed later in
the demuxer's read_close-function; it is the sole reason for said
function's existence. But it is unnecessary, because one can store this
array in the stream's priv_data pointer, so that it will be freed
generically.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavformat/mpc.c

@@ -57,6 +57,7 @@ static int mpc_read_header(AVFormatContext *s)
 {
     MPCContext *c = s->priv_data;
     AVStream *st;
+    int ret;
 
     if(avio_rl24(s->pb) != MKTAG('M', 'P', '+', 0)){
         av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
@@ -72,15 +73,6 @@ static int mpc_read_header(AVFormatContext *s)
         av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
         return AVERROR_INVALIDDATA;
     }
-    if(c->fcount){
-        c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
-        if(!c->frames){
-            av_log(s, AV_LOG_ERROR, "Cannot allocate seektable\n");
-            return AVERROR(ENOMEM);
-        }
-    }else{
-        av_log(s, AV_LOG_WARNING, "Container reports no frames\n");
-    }
     c->curframe = 0;
     c->lastframe = -1;
     c->curbits = 8;
@@ -88,15 +80,27 @@ static int mpc_read_header(AVFormatContext *s)
 
     st = avformat_new_stream(s, NULL);
     if (!st)
-        goto mem_error;
+        return AVERROR(ENOMEM);
+
+    if (c->fcount) {
+        c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
+        if (!c->frames) {
+            av_log(s, AV_LOG_ERROR, "Cannot allocate seektable\n");
+            return AVERROR(ENOMEM);
+        }
+        st->priv_data = c->frames;
+    } else {
+        av_log(s, AV_LOG_WARNING, "Container reports no frames\n");
+    }
+
     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
     st->codecpar->codec_id = AV_CODEC_ID_MUSEPACK7;
     st->codecpar->channels = 2;
     st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
     st->codecpar->bits_per_coded_sample = 16;
 
-    if (ff_get_extradata(s, st->codecpar, s->pb, 16) < 0)
-        goto mem_error;
+    if ((ret = ff_get_extradata(s, st->codecpar, s->pb, 16)) < 0)
+        return ret;
     st->codecpar->sample_rate = mpc_rate[st->codecpar->extradata[2] & 3];
     avpriv_set_pts_info(st, 32, MPC_FRAMESIZE, st->codecpar->sample_rate);
     /* scan for seekpoints */
@@ -113,9 +117,6 @@ static int mpc_read_header(AVFormatContext *s)
     }
 
     return 0;
-mem_error:
-    av_freep(&c->frames);
-    return AVERROR(ENOMEM);
 }
 
 static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
@@ -176,14 +177,6 @@ static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
     return 0;
 }
 
-static int mpc_read_close(AVFormatContext *s)
-{
-    MPCContext *c = s->priv_data;
-
-    av_freep(&c->frames);
-    return 0;
-}
-
 /**
  * Seek to the given position
  * If position is unknown but is within the limits of file
@@ -232,7 +225,6 @@ AVInputFormat ff_mpc_demuxer = {
     .read_probe     = mpc_probe,
     .read_header    = mpc_read_header,
     .read_packet    = mpc_read_packet,
-    .read_close     = mpc_read_close,
     .read_seek      = mpc_read_seek,
     .extensions     = "mpc",
 };