ref: 733c5d6645b133b60d304c38fcb1398f94d0618c
dir: /sys/src/cmd/audio/libFLAC/ogg_decoder_aspect.c/
/* libFLAC - Free Lossless Audio Codec * Copyright (C) 2002-2009 Josh Coalson * Copyright (C) 2011-2022 Xiph.Org Foundation * * 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. */ #ifdef 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" #include "private/macros.h" /*********************************************************************** * * 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 accommodate 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 uint32_t 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 = (uint32_t)(*b); b += FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH; aspect->version_minor = (uint32_t)(*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 = flac_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; }