mpc: return more meaningful error codes.

libavformat/mpc.c

@@ -59,17 +59,17 @@ static int mpc_read_header(AVFormatContext *s)
 
     if(avio_rl24(s->pb) != MKTAG('M', 'P', '+', 0)){
         av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
-        return -1;
+        return AVERROR_INVALIDDATA;
     }
     c->ver = avio_r8(s->pb);
     if(c->ver != 0x07 && c->ver != 0x17){
         av_log(s, AV_LOG_ERROR, "Can demux Musepack SV7, got version %02X\n", c->ver);
-        return -1;
+        return AVERROR_INVALIDDATA;
     }
     c->fcount = avio_rl32(s->pb);
     if((int64_t)c->fcount * sizeof(MPCFrame) >= UINT_MAX){
         av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
-        return -1;
+        return AVERROR_INVALIDDATA;
     }
     if(c->fcount){
         c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
@@ -122,7 +122,7 @@ static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
     int64_t pos;
 
     if (c->curframe >= c->fcount && c->fcount)
-        return -1;
+        return AVERROR_EOF;
 
     if(c->curframe != c->lastframe + 1){
         avio_seek(s->pb, c->frames[c->curframe].pos, SEEK_SET);
@@ -151,8 +151,8 @@ static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
     }
     c->curbits = (curbits + size2) & 0x1F;
 
-    if (av_new_packet(pkt, size) < 0)
-        return AVERROR(EIO);
+    if ((ret = av_new_packet(pkt, size)) < 0)
+        return ret;
 
     pkt->data[0] = curbits;
     pkt->data[1] = (c->curframe > c->fcount) && c->fcount;
@@ -166,7 +166,7 @@ static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
         avio_seek(s->pb, -4, SEEK_CUR);
     if(ret < size){
         av_free_packet(pkt);
-        return AVERROR(EIO);
+        return ret < 0 ? ret : AVERROR(EIO);
     }
     pkt->size = ret + 4;
 
@@ -214,7 +214,7 @@ static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp
         ret = av_read_frame(s, pkt);
         if (ret < 0){
             c->curframe = lastframe;
-            return -1;
+            return ret;
         }
         av_free_packet(pkt);
     }