backport commit r501

fix for  issue 150 ; mp4v2 incorrectly reports track bitrate in the absence of the
avgBitrate track property.  thanks to ktakata65536 for the patch.

diff --git a/src/mp4.cpp b/src/mp4.cpp
index 3605298..e1ea9fd 100644 (file)
--- a/src/mp4.cpp
+++ b/src/mp4.cpp
@@ -2402,8 +2402,11 @@ MP4FileHandle MP4ReadProvider( const char* fileName, const MP4FileProvider* file
         if (MP4_IS_VALID_FILE_HANDLE(hFile)) {
             MP4File *pFile = (MP4File *)hFile;
             try {
-                return pFile->GetTrackIntegerProperty(trackId,
+                uint32_t bitrate = pFile->GetTrackIntegerProperty(trackId,
                                                       "mdia.minf.stbl.stsd.*.esds.decConfigDescr.avgBitrate");
+                if(bitrate != 0) {
+                    return bitrate;
+                }
             }
             catch( Exception* x ) {
                 //mp4v2::impl::log.errorf(*x);  we don't really need to print this.