diff options
Diffstat (limited to 'libFLAC/ogg_decoder_aspect.c')
| -rw-r--r-- | libFLAC/ogg_decoder_aspect.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/libFLAC/ogg_decoder_aspect.c b/libFLAC/ogg_decoder_aspect.c new file mode 100644 index 0000000..6974de3 --- /dev/null +++ b/libFLAC/ogg_decoder_aspect.c @@ -0,0 +1,253 @@ +/* libFLAC - Free Lossless Audio Codec + * Copyright (C) 2002,2003,2004,2005,2006,2007 Josh Coalson + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * - Neither the name of the Xiph.org Foundation nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#if HAVE_CONFIG_H +# include <config.h> +#endif + +#include <string.h> /* for memcpy() */ +#include "FLAC/assert.h" +#include "private/ogg_decoder_aspect.h" +#include "private/ogg_mapping.h" + +#ifdef max +#undef max +#endif +#define max(x,y) ((x)>(y)?(x):(y)) + +/*********************************************************************** + * + * Public class methods + * + ***********************************************************************/ + +FLAC__bool FLAC__ogg_decoder_aspect_init(FLAC__OggDecoderAspect *aspect) +{ + /* we will determine the serial number later if necessary */ + if(ogg_stream_init(&aspect->stream_state, aspect->serial_number) != 0) + return false; + + if(ogg_sync_init(&aspect->sync_state) != 0) + return false; + + aspect->version_major = ~(0u); + aspect->version_minor = ~(0u); + + aspect->need_serial_number = aspect->use_first_serial_number; + + aspect->end_of_stream = false; + aspect->have_working_page = false; + + return true; +} + +void FLAC__ogg_decoder_aspect_finish(FLAC__OggDecoderAspect *aspect) +{ + (void)ogg_sync_clear(&aspect->sync_state); + (void)ogg_stream_clear(&aspect->stream_state); +} + +void FLAC__ogg_decoder_aspect_set_serial_number(FLAC__OggDecoderAspect *aspect, long value) +{ + aspect->use_first_serial_number = false; + aspect->serial_number = value; +} + +void FLAC__ogg_decoder_aspect_set_defaults(FLAC__OggDecoderAspect *aspect) +{ + aspect->use_first_serial_number = true; +} + +void FLAC__ogg_decoder_aspect_flush(FLAC__OggDecoderAspect *aspect) +{ + (void)ogg_stream_reset(&aspect->stream_state); + (void)ogg_sync_reset(&aspect->sync_state); + aspect->end_of_stream = false; + aspect->have_working_page = false; +} + +void FLAC__ogg_decoder_aspect_reset(FLAC__OggDecoderAspect *aspect) +{ + FLAC__ogg_decoder_aspect_flush(aspect); + + if(aspect->use_first_serial_number) + aspect->need_serial_number = true; +} + +FLAC__OggDecoderAspectReadStatus FLAC__ogg_decoder_aspect_read_callback_wrapper(FLAC__OggDecoderAspect *aspect, FLAC__byte buffer[], size_t *bytes, FLAC__OggDecoderAspectReadCallbackProxy read_callback, const FLAC__StreamDecoder *decoder, void *client_data) +{ + static const size_t OGG_BYTES_CHUNK = 8192; + const size_t bytes_requested = *bytes; + + /* + * The FLAC decoding API uses pull-based reads, whereas Ogg decoding + * is push-based. In libFLAC, when you ask to decode a frame, the + * decoder will eventually call the read callback to supply some data, + * but how much it asks for depends on how much free space it has in + * its internal buffer. It does not try to grow its internal buffer + * to accomodate a whole frame because then the internal buffer size + * could not be limited, which is necessary in embedded applications. + * + * Ogg however grows its internal buffer until a whole page is present; + * only then can you get decoded data out. So we can't just ask for + * the same number of bytes from Ogg, then pass what's decoded down to + * libFLAC. If what libFLAC is asking for will not contain a whole + * page, then we will get no data from ogg_sync_pageout(), and at the + * same time cannot just read more data from the client for the purpose + * of getting a whole decoded page because the decoded size might be + * larger than libFLAC's internal buffer. + * + * Instead, whenever this read callback wrapper is called, we will + * continually request data from the client until we have at least one + * page, and manage pages internally so that we can send pieces of + * pages down to libFLAC in such a way that we obey its size + * requirement. To limit the amount of callbacks, we will always try + * to read in enough pages to return the full number of bytes + * requested. + */ + *bytes = 0; + while (*bytes < bytes_requested && !aspect->end_of_stream) { + if (aspect->have_working_page) { + if (aspect->have_working_packet) { + size_t n = bytes_requested - *bytes; + if ((size_t)aspect->working_packet.bytes <= n) { + /* the rest of the packet will fit in the buffer */ + n = aspect->working_packet.bytes; + memcpy(buffer, aspect->working_packet.packet, n); + *bytes += n; + buffer += n; + aspect->have_working_packet = false; + } + else { + /* only n bytes of the packet will fit in the buffer */ + memcpy(buffer, aspect->working_packet.packet, n); + *bytes += n; + buffer += n; + aspect->working_packet.packet += n; + aspect->working_packet.bytes -= n; + } + } + else { + /* try and get another packet */ + const int ret = ogg_stream_packetout(&aspect->stream_state, &aspect->working_packet); + if (ret > 0) { + aspect->have_working_packet = true; + /* if it is the first header packet, check for magic and a supported Ogg FLAC mapping version */ + if (aspect->working_packet.bytes > 0 && aspect->working_packet.packet[0] == FLAC__OGG_MAPPING_FIRST_HEADER_PACKET_TYPE) { + const FLAC__byte *b = aspect->working_packet.packet; + const unsigned header_length = + FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH + + FLAC__OGG_MAPPING_MAGIC_LENGTH + + FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH + + FLAC__OGG_MAPPING_VERSION_MINOR_LENGTH + + FLAC__OGG_MAPPING_NUM_HEADERS_LENGTH; + if (aspect->working_packet.bytes < (long)header_length) + return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC; + b += FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH; + if (memcmp(b, FLAC__OGG_MAPPING_MAGIC, FLAC__OGG_MAPPING_MAGIC_LENGTH)) + return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC; + b += FLAC__OGG_MAPPING_MAGIC_LENGTH; + aspect->version_major = (unsigned)(*b); + b += FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH; + aspect->version_minor = (unsigned)(*b); + if (aspect->version_major != 1) + return FLAC__OGG_DECODER_ASPECT_READ_STATUS_UNSUPPORTED_MAPPING_VERSION; + aspect->working_packet.packet += header_length; + aspect->working_packet.bytes -= header_length; + } + } + else if (ret == 0) { + aspect->have_working_page = false; + } + else { /* ret < 0 */ + /* lost sync, we'll leave the working page for the next call */ + return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC; + } + } + } + else { + /* try and get another page */ + const int ret = ogg_sync_pageout(&aspect->sync_state, &aspect->working_page); + if (ret > 0) { + /* got a page, grab the serial number if necessary */ + if(aspect->need_serial_number) { + aspect->stream_state.serialno = aspect->serial_number = ogg_page_serialno(&aspect->working_page); + aspect->need_serial_number = false; + } + if(ogg_stream_pagein(&aspect->stream_state, &aspect->working_page) == 0) { + aspect->have_working_page = true; + aspect->have_working_packet = false; + } + /* else do nothing, could be a page from another stream */ + } + else if (ret == 0) { + /* need more data */ + const size_t ogg_bytes_to_read = max(bytes_requested - *bytes, OGG_BYTES_CHUNK); + char *oggbuf = ogg_sync_buffer(&aspect->sync_state, ogg_bytes_to_read); + + if(0 == oggbuf) { + return FLAC__OGG_DECODER_ASPECT_READ_STATUS_MEMORY_ALLOCATION_ERROR; + } + else { + size_t ogg_bytes_read = ogg_bytes_to_read; + + switch(read_callback(decoder, (FLAC__byte*)oggbuf, &ogg_bytes_read, client_data)) { + case FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK: + break; + case FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM: + aspect->end_of_stream = true; + break; + case FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT: + return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT; + default: + FLAC__ASSERT(0); + } + + if(ogg_sync_wrote(&aspect->sync_state, ogg_bytes_read) < 0) { + /* double protection; this will happen if the read callback returns more bytes than the max requested, which would overflow Ogg's internal buffer */ + FLAC__ASSERT(0); + return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ERROR; + } + } + } + else { /* ret < 0 */ + /* lost sync, bail out */ + return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC; + } + } + } + + if (aspect->end_of_stream && *bytes == 0) { + return FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM; + } + + return FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK; +} |