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change unparseable frame handling, from a fatal error and FLAC__STREAM_DECODER_UNPARSEABLE_STREAM state, to a soft error FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM

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This commit is contained in:
Josh Coalson
2006-07-06 07:49:07 +00:00
parent 4cbb812521
commit 1a8afc7031
4 changed files with 93 additions and 78 deletions
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7
doc/html/changelog.html
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@@ -66,7 +66,7 @@
General:
<ul>
<li>Large file (&gt;2GB) support everywhere</li>
<li>Better recovery for corrupted files</li>
<li>Much better recovery for corrupted files</li>
</ul>
</li>
<li>
@@ -84,7 +84,7 @@
<li>
flac:
<ul>
<li>Improved the <a href="documentation.html#flac_options_decode_through_errors"><span class="argument">-F</span></a> to allow decoding of FLAC files whose metadata is corrupted.</li>
<li>Improved the <a href="documentation.html#flac_options_decode_through_errors"><span class="argument">-F</span></a> to allow decoding of FLAC files whose metadata is corrupted, and other kinds of corruption.</li>
<li>Added a new option <a href="documentation.html#flac_options_tag_from_file"><span class="argument">--tag-from-file</span></a> for setting a tag from file (e.g. for importing a cuesheet as a tag).</li>
<li>Added support for encoding from non-compressed AIFF-C (<a href="https://sourceforge.net/tracker/?func=detail&amp;atid=113478&amp;aid=1090933&amp;group_id=13478">SF #1090933</a>).</li>
<li>Importing of non-CDDA-compliant cuesheets now only issues a warning, not an error (see <a href="http://www.hydrogenaudio.org/forums/index.php?showtopic=31282">here</a>).</li>
@@ -139,6 +139,9 @@
<li><b>Added</b> FLAC__*_encoder_set_apodization()</li>
<li><b>Added</b> FLAC__metadata_object_cuesheet_calculate_cddb_id()</li>
<li><b>Added</b> FLAC__metadata_get_cuesheet()</li>
<li><b>Changed</b> FLAC__StreamDecoderState: removed state FLAC__STREAM_DECODER_UNPARSEABLE_STREAM</li>
<li><b>Changed</b> FLAC__StreamDecoderErrorStatus: new error code FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM</li>
<li>The above two changes mean that when the decoder encounters what it thinks are unparseable frames from a future decoder, instead of returning a fatal error with the FLAC__STREAM_DECODER_UNPARSEABLE_STREAM state, it just calls the error callback with FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM and leaves the behavior up to the application.</li>
</ul>
</li>
<li>

73
include/FLAC/stream_decoder.h
View File

@@ -213,9 +213,6 @@ typedef enum {
FLAC__STREAM_DECODER_ABORTED,
/**< The decoder was aborted by the read callback. */
FLAC__STREAM_DECODER_UNPARSEABLE_STREAM,
/**< The decoder encountered reserved fields in use in the stream. */
FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR,
/**< An error occurred allocating memory. */
@@ -284,7 +281,20 @@ typedef enum {
extern FLAC_API const char * const FLAC__StreamDecoderWriteStatusString[];
/** Possible values passed in to the FLAC__StreamDecoder error callback.
/** Possible values passed back to the FLAC__StreamDecoder error callback.
* \c FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC is the generic catch-
* all. The rest could be caused by bad sync (false synchronization on
* data that is not the start of a frame) or corrupted data. The error
* itself is the decoder's best guess at what happened assuming a correct
* sync. For example \c FLAC__STREAM_DECODER_ERROR_STATUS_BAD_HEADER
* could be caused by a correct sync on the start of a frame, but some
* data in the frame header was corrupted. Or it could be the result of
* syncing on a point the stream that looked like the starting of a frame
* but was not. \c FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM
* could be because the decoder encountered a valid frame made by a future
* version of the encoder which it cannot parse, or because of a false
* sync making it appear as though an encountered frame was generated by
* a future encoder.
*/
typedef enum {
@@ -294,9 +304,12 @@ typedef enum {
FLAC__STREAM_DECODER_ERROR_STATUS_BAD_HEADER,
/**< The decoder encountered a corrupted frame header. */
FLAC__STREAM_DECODER_ERROR_STATUS_FRAME_CRC_MISMATCH
FLAC__STREAM_DECODER_ERROR_STATUS_FRAME_CRC_MISMATCH,
/**< The frame's data did not match the CRC in the footer. */
FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM
/**< The decoder encountered reserved fields in use in the stream. */
} FLAC__StreamDecoderErrorStatus;
/** Maps a FLAC__StreamDecoderErrorStatus to a C string.
@@ -747,16 +760,14 @@ FLAC_API FLAC__bool FLAC__stream_decoder_reset(FLAC__StreamDecoder *decoder);
*
* As the decoder needs more input it will call the read callback.
* Depending on what was decoded, the metadata or write callback will be
* called with the decoded metadata block or audio frame, unless an error
* occurred. If the decoder loses sync it will call the error callback
* instead.
* called with the decoded metadata block or audio frame.
*
* Unless there is a fatal read error or end of stream, this function
* will return once one whole frame is decoded. In other words, if the
* stream is not synchronized or points to a corrupt frame header, the
* decoder will continue to try and resync until it gets to a valid
* frame, then decode one frame, then return. If the decoder points to
* frame whose frame CRC in the frame footer does not match the
* a frame whose frame CRC in the frame footer does not match the
* computed frame CRC, this function will issue a
* FLAC__STREAM_DECODER_ERROR_STATUS_FRAME_CRC_MISMATCH error to the
* error callback, and return, having decoded one complete, although
@@ -767,11 +778,10 @@ FLAC_API FLAC__bool FLAC__stream_decoder_reset(FLAC__StreamDecoder *decoder);
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__bool
* \c false if any read or write error occurred (except
* \c FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC), else \c true;
* in any case, check the decoder state with
* FLAC__stream_decoder_get_state() to see what went wrong or to
* check for lost synchronization (a sign of stream corruption).
* \c false if any fatal read, write, or memory allocation error
* occurred (meaning decoding must stop), else \c true; for more
* information about the decoder, check the decoder state with
* FLAC__stream_decoder_get_state().
*/
FLAC_API FLAC__bool FLAC__stream_decoder_process_single(FLAC__StreamDecoder *decoder);
@@ -783,18 +793,16 @@ FLAC_API FLAC__bool FLAC__stream_decoder_process_single(FLAC__StreamDecoder *dec
*
* As the decoder needs more input it will call the read callback.
* As each metadata block is decoded, the metadata callback will be called
* with the decoded metadata. If the decoder loses sync it will call the
* error callback.
* with the decoded metadata.
*
* \param decoder An initialized decoder instance.
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__bool
* \c false if any read or write error occurred (except
* \c FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC), else \c true;
* in any case, check the decoder state with
* FLAC__stream_decoder_get_state() to see what went wrong or to
* check for lost synchronization (a sign of stream corruption).
* \c false if any fatal read, write, or memory allocation error
* occurred (meaning decoding must stop), else \c true; for more
* information about the decoder, check the decoder state with
* FLAC__stream_decoder_get_state().
*/
FLAC_API FLAC__bool FLAC__stream_decoder_process_until_end_of_metadata(FLAC__StreamDecoder *decoder);
@@ -806,18 +814,16 @@ FLAC_API FLAC__bool FLAC__stream_decoder_process_until_end_of_metadata(FLAC__Str
*
* As the decoder needs more input it will call the read callback.
* As each metadata block and frame is decoded, the metadata or write
* callback will be called with the decoded metadata or frame. If the
* decoder loses sync it will call the error callback.
* callback will be called with the decoded metadata or frame.
*
* \param decoder An initialized decoder instance.
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__bool
* \c false if any read or write error occurred (except
* \c FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC), else \c true;
* in any case, check the decoder state with
* FLAC__stream_decoder_get_state() to see what went wrong or to
* check for lost synchronization (a sign of stream corruption).
* \c false if any fatal read, write, or memory allocation error
* occurred (meaning decoding must stop), else \c true; for more
* information about the decoder, check the decoder state with
* FLAC__stream_decoder_get_state().
*/
FLAC_API FLAC__bool FLAC__stream_decoder_process_until_end_of_stream(FLAC__StreamDecoder *decoder);
@@ -854,13 +860,12 @@ FLAC_API FLAC__bool FLAC__stream_decoder_process_until_end_of_stream(FLAC__Strea
* \assert
* \code decoder != NULL \endcode
* \retval FLAC__bool
* \c false if any read or write error occurred (except
* \c FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC), or if the decoder
* \c false if any fatal read, write, or memory allocation error
* occurred (meaning decoding must stop), or if the decoder
* is in the FLAC__STREAM_DECODER_SEARCH_FOR_METADATA or
* FLAC__STREAM_DECODER_READ_METADATA state, else \c true;
* in any case, check the decoder state with
* FLAC__stream_decoder_get_state() to see what went wrong or to
* check for lost synchronization (a sign of stream corruption).
* FLAC__STREAM_DECODER_READ_METADATA state, else \c true; for more
* information about the decoder, check the decoder state with
* FLAC__stream_decoder_get_state().
*/
FLAC_API FLAC__bool FLAC__stream_decoder_skip_single_frame(FLAC__StreamDecoder *decoder);

46
src/libFLAC/seekable_stream_decoder.c
View File

@@ -91,6 +91,7 @@ typedef struct FLAC__SeekableStreamDecoderPrivate {
FLAC__bool ignore_seek_table_block;
FLAC__Frame last_frame; /* holds the info of the last frame we seeked to */
FLAC__uint64 target_sample;
unsigned unparseable_frame_count; /* used to tell whether we're decoding a future version of FLAC or just got a bad sync */
} FLAC__SeekableStreamDecoderPrivate;
/***********************************************************************
@@ -217,6 +218,7 @@ FLAC_API FLAC__SeekableStreamDecoderState FLAC__seekable_stream_decoder_init(FLA
decoder->private_->do_md5_checking = decoder->protected_->md5_checking;
decoder->private_->got_stream_info = false;
decoder->private_->unparseable_frame_count = 0;
/* We initialize the FLAC__MD5Context even though we may never use it. This
* is because md5 checking may be turned on to start and then turned off if
@@ -755,6 +757,18 @@ FLAC__StreamDecoderReadStatus read_callback_(const FLAC__StreamDecoder *decoder,
return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
}
else if(*bytes > 0) {
/* While seeking, it is possible for our seek to land in the
* middle of audio data that looks exactly like a frame header
* from a future version of an encoder. When that happens, our
* error callback will get an
* FLAC__STREAM_DECODER_UNPARSEABLE_STREAM and increment its
* unparseable_frame_count. But there is a remote possibility
* that it is properly synced at such a "future-codec frame",
* so to make sure, we wait to see many "unparseable" errors in
* a row before bailing out.
*/
if(seekable_stream_decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_SEEKING && seekable_stream_decoder->private_->unparseable_frame_count > 20)
return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
if(seekable_stream_decoder->private_->read_callback(seekable_stream_decoder, buffer, bytes, seekable_stream_decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_READ_STATUS_OK) {
seekable_stream_decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_READ_ERROR;
return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
@@ -859,6 +873,8 @@ void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErro
if(seekable_stream_decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_SEEKING)
seekable_stream_decoder->private_->error_callback(seekable_stream_decoder, status, seekable_stream_decoder->private_->client_data);
else if(status == FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM)
seekable_stream_decoder->private_->unparseable_frame_count++;
}
FLAC__bool seek_to_absolute_sample_(FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 stream_length, FLAC__uint64 target_sample)
@@ -1040,33 +1056,17 @@ FLAC__bool seek_to_absolute_sample_(FLAC__SeekableStreamDecoder *decoder, FLAC__
return false;
}
}
/* Now we need to get a frame. It is possible for our seek
* to land in the middle of audio data that looks exactly like
* a frame header from a future version of an encoder. When
* that happens, FLAC__stream_decoder_process_single() will
* return false and the state will be
* FLAC__STREAM_DECODER_UNPARSEABLE_STREAM. But there is a
* remote possibility that it is properly synced at such a
* "future-codec frame", so to make sure, we wait to see
* several "unparseable" errors in a row before bailing out.
/* Now we need to get a frame. First we need to reset our
* unparseable_frame_count; if we get too many unparseable
* frames in a row, the read callback will return
* FLAC__STREAM_DECODER_READ_STATUS_ABORT, causing
* FLAC__stream_decoder_process_single() to return false.
*/
{
unsigned unparseable_count;
FLAC__bool got_a_frame = false;
for (unparseable_count = 0; !got_a_frame && unparseable_count < 10; unparseable_count++) {
if(FLAC__stream_decoder_process_single(decoder->private_->stream_decoder))
got_a_frame = true;
else if(decoder->private_->stream_decoder->protected_->state == FLAC__STREAM_DECODER_UNPARSEABLE_STREAM)
/* try again. we don't want to flush the decoder since that clears the bitbuffer */
decoder->private_->stream_decoder->protected_->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
else /* it's a real error */
break;
}
if (!got_a_frame) {
decoder->private_->unparseable_frame_count = 0;
if(!FLAC__stream_decoder_process_single(decoder->private_->stream_decoder)) {
decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
return false;
}
}
/* our write callback will change the state when it gets to the target frame */
/* actually, we could have got_a_frame if our decoder is at FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM so we need to check for that also */
if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_SEEKING && decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM) {

41
src/libFLAC/stream_decoder.c
View File

@@ -151,7 +151,6 @@ FLAC_API const char * const FLAC__StreamDecoderStateString[] = {
"FLAC__STREAM_DECODER_READ_FRAME",
"FLAC__STREAM_DECODER_END_OF_STREAM",
"FLAC__STREAM_DECODER_ABORTED",
"FLAC__STREAM_DECODER_UNPARSEABLE_STREAM",
"FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR",
"FLAC__STREAM_DECODER_ALREADY_INITIALIZED",
"FLAC__STREAM_DECODER_INVALID_CALLBACK",
@@ -172,7 +171,8 @@ FLAC_API const char * const FLAC__StreamDecoderWriteStatusString[] = {
FLAC_API const char * const FLAC__StreamDecoderErrorStatusString[] = {
"FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC",
"FLAC__STREAM_DECODER_ERROR_STATUS_BAD_HEADER",
"FLAC__STREAM_DECODER_ERROR_STATUS_FRAME_CRC_MISMATCH"
"FLAC__STREAM_DECODER_ERROR_STATUS_FRAME_CRC_MISMATCH",
"FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM"
};
/***********************************************************************
@@ -1399,7 +1399,7 @@ FLAC__bool read_frame_(FLAC__StreamDecoder *decoder, FLAC__bool *got_a_frame, FL
if(!read_frame_header_(decoder))
return false;
if(decoder->protected_->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC)
if(decoder->protected_->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC) /* means we didn't sync on a valid header */
return true;
if(!allocate_output_(decoder, decoder->private_->frame.header.blocksize, decoder->private_->frame.header.channels))
return false;
@@ -1435,11 +1435,9 @@ FLAC__bool read_frame_(FLAC__StreamDecoder *decoder, FLAC__bool *got_a_frame, FL
*/
if(!read_subframe_(decoder, channel, bps, do_full_decode))
return false;
if(decoder->protected_->state != FLAC__STREAM_DECODER_READ_FRAME) {
decoder->protected_->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
if(decoder->protected_->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC) /* means bad sync or got corruption */
return true;
}
}
if(!read_zero_padding_(decoder))
return false;
@@ -1813,8 +1811,9 @@ FLAC__bool read_frame_header_(FLAC__StreamDecoder *decoder)
}
if(is_unparseable) {
decoder->protected_->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
return false;
decoder->private_->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM, decoder->private_->client_data);
decoder->protected_->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
return true;
}
return true;
@@ -1824,6 +1823,7 @@ FLAC__bool read_subframe_(FLAC__StreamDecoder *decoder, unsigned channel, unsign
{
FLAC__uint32 x;
FLAC__bool wasted_bits;
unsigned i;
if(!FLAC__bitbuffer_read_raw_uint32(decoder->private_->input, &x, 8, read_callback_, decoder)) /* MAGIC NUMBER */
return false; /* the read_callback_ sets the state for us */
@@ -1858,24 +1858,29 @@ FLAC__bool read_subframe_(FLAC__StreamDecoder *decoder, unsigned channel, unsign
return false;
}
else if(x < 16) {
decoder->protected_->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
return false;
decoder->private_->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM, decoder->private_->client_data);
decoder->protected_->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
return true;
}
else if(x <= 24) {
if(!read_subframe_fixed_(decoder, channel, bps, (x>>1)&7, do_full_decode))
return false;
if(decoder->protected_->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC) /* means bad sync or got corruption */
return true;
}
else if(x < 64) {
decoder->protected_->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
return false;
decoder->private_->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM, decoder->private_->client_data);
decoder->protected_->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
return true;
}
else {
if(!read_subframe_lpc_(decoder, channel, bps, ((x>>1)&31)+1, do_full_decode))
return false;
if(decoder->protected_->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC) /* means bad sync or got corruption */
return true;
}
if(wasted_bits && do_full_decode) {
unsigned i;
x = decoder->private_->frame.subframes[channel].wasted_bits;
for(i = 0; i < decoder->private_->frame.header.blocksize; i++)
decoder->private_->output[channel][i] <<= x;
@@ -1938,8 +1943,9 @@ FLAC__bool read_subframe_fixed_(FLAC__StreamDecoder *decoder, unsigned channel,
subframe->entropy_coding_method.data.partitioned_rice.contents = &decoder->private_->partitioned_rice_contents[channel];
break;
default:
decoder->protected_->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
return false;
decoder->private_->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM, decoder->private_->client_data);
decoder->protected_->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
return true;
}
/* read residual */
@@ -2014,8 +2020,9 @@ FLAC__bool read_subframe_lpc_(FLAC__StreamDecoder *decoder, unsigned channel, un
subframe->entropy_coding_method.data.partitioned_rice.contents = &decoder->private_->partitioned_rice_contents[channel];
break;
default:
decoder->protected_->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
return false;
decoder->private_->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM, decoder->private_->client_data);
decoder->protected_->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
return true;
}
/* read residual */