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