• ogg_helper.c
  • /* libFLAC - Free Lossless Audio Codec
     * Copyright (C) 2004-2009  Josh Coalson
     * Copyright (C) 2011-2025  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 <stdlib.h> /* for malloc() */
    #include <string.h> /* for memcmp(), memcpy() */
    #include "FLAC/assert.h"
    #include "share/alloc.h"
    #include "private/ogg_helper.h"
    #include "protected/stream_encoder.h"
    
    
    static FLAC__bool full_read_(FLAC__StreamEncoder *encoder, FLAC__byte *buffer, size_t bytes, FLAC__StreamEncoderReadCallback read_callback, void *client_data)
    {
    	while(bytes > 0) {
    		size_t bytes_read = bytes;
    		switch(read_callback(encoder, buffer, &bytes_read, client_data)) {
    			case FLAC__STREAM_ENCODER_READ_STATUS_CONTINUE:
    				bytes -= bytes_read;
    				buffer += bytes_read;
    				break;
    			case FLAC__STREAM_ENCODER_READ_STATUS_END_OF_STREAM:
    				if(bytes_read == 0) {
    					encoder->protected_->state = FLAC__STREAM_ENCODER_OGG_ERROR;
    					return false;
    				}
    				bytes -= bytes_read;
    				buffer += bytes_read;
    				break;
    			case FLAC__STREAM_ENCODER_READ_STATUS_ABORT:
    				encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;
    				return false;
    			case FLAC__STREAM_ENCODER_READ_STATUS_UNSUPPORTED:
    				return false;
    			default:
    				/* double protection: */
    				FLAC__ASSERT(0);
    				encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;
    				return false;
    		}
    	}
    
    	return true;
    }
    
    void simple_ogg_page__init(ogg_page *page)
    {
    	page->header = 0;
    	page->header_len = 0;
    	page->body = 0;
    	page->body_len = 0;
    }
    
    void simple_ogg_page__clear(ogg_page *page)
    {
    	if(page->header)
    		free(page->header);
    	if(page->body)
    		free(page->body);
    	simple_ogg_page__init(page);
    }
    
    FLAC__bool simple_ogg_page__get_at(FLAC__StreamEncoder *encoder, FLAC__uint64 position, ogg_page *page, FLAC__StreamEncoderSeekCallback seek_callback, FLAC__StreamEncoderReadCallback read_callback, void *client_data)
    {
    	static const uint32_t OGG_HEADER_FIXED_PORTION_LEN = 27;
    	static const uint32_t OGG_MAX_HEADER_LEN = 27/*OGG_HEADER_FIXED_PORTION_LEN*/ + 255;
    	FLAC__byte crc[4];
    	FLAC__StreamEncoderSeekStatus seek_status;
    
    	FLAC__ASSERT(page->header == 0);
    	FLAC__ASSERT(page->header_len == 0);
    	FLAC__ASSERT(page->body == 0);
    	FLAC__ASSERT(page->body_len == 0);
    
    	/* move the stream pointer to the supposed beginning of the page */
    	if(0 == seek_callback)
    		return false;
    	if((seek_status = seek_callback((FLAC__StreamEncoder*)encoder, position, client_data)) != FLAC__STREAM_ENCODER_SEEK_STATUS_OK) {
    		if(seek_status == FLAC__STREAM_ENCODER_SEEK_STATUS_ERROR)
    			encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;
    		return false;
    	}
    
    	/* allocate space for the page header */
    	if(0 == (page->header = safe_malloc_(OGG_MAX_HEADER_LEN))) {
    		encoder->protected_->state = FLAC__STREAM_ENCODER_MEMORY_ALLOCATION_ERROR;
    		return false;
    	}
    
    	/* read in the fixed part of the page header (up to but not including
    	 * the segment table */
    	if(!full_read_(encoder, page->header, OGG_HEADER_FIXED_PORTION_LEN, read_callback, client_data))
    		return false;
    
    	page->header_len = OGG_HEADER_FIXED_PORTION_LEN + page->header[26];
    
    	/* check to see if it's a correct, "simple" page (one packet only) */
    	if(
    		memcmp(page->header, "OggS", 4) ||               /* doesn't start with OggS */
    		(page->header[5] & 0x01) ||                      /* continued packet */
    		memcmp(page->header+6, "\0\0\0\0\0\0\0\0", 8) || /* granulepos is non-zero */
    		page->header[26] == 0                            /* packet is 0-size */
    	) {
    		encoder->protected_->state = FLAC__STREAM_ENCODER_OGG_ERROR;
    		return false;
    	}
    
    	/* read in the segment table */
    	if(!full_read_(encoder, page->header + OGG_HEADER_FIXED_PORTION_LEN, page->header[26], read_callback, client_data))
    		return false;
    
    	{
    		uint32_t i;
    
    		/* check to see that it specifies a single packet */
    		for(i = 0; i < (uint32_t)page->header[26] - 1; i++) {
    			if(page->header[i + OGG_HEADER_FIXED_PORTION_LEN] != 255) {
    				encoder->protected_->state = FLAC__STREAM_ENCODER_OGG_ERROR;
    				return false;
    			}
    		}
    
    		page->body_len = 255 * i + page->header[i + OGG_HEADER_FIXED_PORTION_LEN];
    	}
    
    	/* allocate space for the page body */
    	if(0 == (page->body = safe_malloc_(page->body_len))) {
    		encoder->protected_->state = FLAC__STREAM_ENCODER_MEMORY_ALLOCATION_ERROR;
    		return false;
    	}
    
    	/* read in the page body */
    	if(!full_read_(encoder, page->body, page->body_len, read_callback, client_data))
    		return false;
    
    	/* check the CRC */
    	memcpy(crc, page->header+22, 4);
    	ogg_page_checksum_set(page);
    	if(memcmp(crc, page->header+22, 4)) {
    		encoder->protected_->state = FLAC__STREAM_ENCODER_OGG_ERROR;
    		return false;
    	}
    
    	return true;
    }
    
    FLAC__bool simple_ogg_page__set_at(FLAC__StreamEncoder *encoder, FLAC__uint64 position, ogg_page *page, FLAC__StreamEncoderSeekCallback seek_callback, FLAC__StreamEncoderWriteCallback write_callback, void *client_data)
    {
    	FLAC__StreamEncoderSeekStatus seek_status;
    
    	FLAC__ASSERT(page->header != 0);
    	FLAC__ASSERT(page->header_len != 0);
    	FLAC__ASSERT(page->body != 0);
    	FLAC__ASSERT(page->body_len != 0);
    
    	/* move the stream pointer to the supposed beginning of the page */
    	if(0 == seek_callback)
    		return false;
    	if((seek_status = seek_callback((FLAC__StreamEncoder*)encoder, position, client_data)) != FLAC__STREAM_ENCODER_SEEK_STATUS_OK) {
    		if(seek_status == FLAC__STREAM_ENCODER_SEEK_STATUS_ERROR)
    			encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;
    		return false;
    	}
    
    	ogg_page_checksum_set(page);
    
    	/* re-write the page */
    	if(write_callback((FLAC__StreamEncoder*)encoder, page->header, page->header_len, 0, 0, client_data) != FLAC__STREAM_ENCODER_WRITE_STATUS_OK) {
    		encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;
    		return false;
    	}
    	if(write_callback((FLAC__StreamEncoder*)encoder, page->body, page->body_len, 0, 0, client_data) != FLAC__STREAM_ENCODER_WRITE_STATUS_OK) {
    		encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;
    		return false;
    	}
    
    	return true;
    }