diff options
| -rw-r--r-- | doc/html/changelog.html | 1 | ||||
| -rw-r--r-- | doc/html/format.html | 17 | ||||
| -rw-r--r-- | src/libFLAC/stream_decoder.c | 4 |
3 files changed, 13 insertions, 9 deletions
diff --git a/doc/html/changelog.html b/doc/html/changelog.html index 9595085f..db1229da 100644 --- a/doc/html/changelog.html +++ b/doc/html/changelog.html @@ -121,6 +121,7 @@ <ul> <li>libFLAC encoder was defaulting to level 0 compression instead of 5 (<a href="https://sourceforge.net/tracker2/?func=detail&aid=1816825&group_id=13478&atid=113478">SF #1816825</a>).</li> <li>Fix bug in bitreader handling of read callback returning a short count (<a href="https://sourceforge.net/tracker2/?func=detail&aid=2490454&group_id=13478&atid=113478">SF #2490454</a>).</li> + <li>Improve decoder's ability to distinguish between a FLAC sync code and an MPEG one (<a href="https://sourceforge.net/tracker2/?func=detail&aid=2491433&group_id=13478&atid=113478">SF #2491433</a>).</li> </ul> </li> <li> diff --git a/doc/html/format.html b/doc/html/format.html index 98b30b0a..a9294dba 100644 --- a/doc/html/format.html +++ b/doc/html/format.html @@ -1121,7 +1121,7 @@ <1> </td> <td> - Reserved:<br /> + Reserved: <a href="#frame_header_notes">[1]</a><br /> <ul> <li> <tt>0</tt> : mandatory value @@ -1137,7 +1137,7 @@ <1> </td> <td> - Blocking strategy:<br /> + Blocking strategy: <a href="#frame_header_notes">[2]</a> <a href="#frame_header_notes">[3]</a><br /> <ul> <li> <tt>0</tt> : fixed-blocksize stream; frame header encodes the frame number @@ -1325,9 +1325,9 @@ </td> <td> if(variable blocksize)<br /> - <8-56>:"UTF-8" coded sample number (decoded number is 36 bits)<br /> + <8-56>:"UTF-8" coded sample number (decoded number is 36 bits) <a href="#frame_header_notes">[4]</a><br /> else<br /> - <8-48>:"UTF-8" coded frame number (decoded number is 31 bits) + <8-48>:"UTF-8" coded frame number (decoded number is 31 bits) <a href="#frame_header_notes">[4]</a> </td> </tr> <tr> @@ -1360,8 +1360,11 @@ <td> </td> <td bgcolor="#F4F4CC"> - <font size="+1">NOTES</font><br /> - <ul> + <a name="frame_header_notes"><font size="+1">NOTES</font></a><br /> + <ol> + <li> + This bit must remain reserved for <tt>0</tt> in order for a FLAC frame's initial 15 bits to be distinguishable from the start of an MPEG audio frame (<a href="http://lists.xiph.org/pipermail/flac-dev/2008-December/002607.html">see also</a>). + </li> <li> The "blocking strategy" bit must be the same throughout the entire stream. </li> @@ -1371,7 +1374,7 @@ <li> The "UTF-8" coding used for the sample/frame number is the same variable length code used to store compressed UCS-2, extended to handle larger input. </li> - </ul> + </ol> </td> </tr> </table> diff --git a/src/libFLAC/stream_decoder.c b/src/libFLAC/stream_decoder.c index 8756d6f1..75f896a3 100644 --- a/src/libFLAC/stream_decoder.c +++ b/src/libFLAC/stream_decoder.c @@ -1407,7 +1407,7 @@ FLAC__bool find_metadata_(FLAC__StreamDecoder *decoder) decoder->private_->lookahead = (FLAC__byte)x; decoder->private_->cached = true; } - else if(x >> 2 == 0x3e) { /* MAGIC NUMBER for the last 6 sync bits */ + else if(x >> 1 == 0x7c) { /* MAGIC NUMBER for the last 6 sync bits and reserved 7th bit */ decoder->private_->header_warmup[1] = (FLAC__byte)x; decoder->protected_->state = FLAC__STREAM_DECODER_READ_FRAME; return true; @@ -1977,7 +1977,7 @@ FLAC__bool frame_sync_(FLAC__StreamDecoder *decoder) decoder->private_->lookahead = (FLAC__byte)x; decoder->private_->cached = true; } - else if(x >> 2 == 0x3e) { /* MAGIC NUMBER for the last 6 sync bits */ + else if(x >> 1 == 0x7c) { /* MAGIC NUMBER for the last 6 sync bits and reserved 7th bit */ decoder->private_->header_warmup[1] = (FLAC__byte)x; decoder->protected_->state = FLAC__STREAM_DECODER_READ_FRAME; return true; |