summaryrefslogtreecommitdiff
path: root/libmad/src/frame.c
diff options
context:
space:
mode:
Diffstat (limited to 'libmad/src/frame.c')
-rw-r--r--libmad/src/frame.c512
1 files changed, 0 insertions, 512 deletions
diff --git a/libmad/src/frame.c b/libmad/src/frame.c
deleted file mode 100644
index 37acbfa..0000000
--- a/libmad/src/frame.c
+++ /dev/null
@@ -1,512 +0,0 @@
-/*
- * libmad - MPEG audio decoder library
- * Copyright (C) 2000-2004 Underbit Technologies, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * $Id: frame.c,v 1.29 2004/02/04 22:59:19 rob Exp $
- */
-
-# ifdef HAVE_CONFIG_H
-# include "config.h"
-# endif
-
-# include "global.h"
-
-# include <stdlib.h>
-
-# include "bit.h"
-# include "stream.h"
-# include "frame.h"
-# include "timer.h"
-# include "layer12.h"
-# include "layer3.h"
-
-# ifdef _MSC_VER
-# pragma warning(push)
-# pragma warning(disable: 4244 4018)
-# endif
-
-static
-unsigned long const bitrate_table[5][15] = {
- /* MPEG-1 */
- { 0, 32000, 64000, 96000, 128000, 160000, 192000, 224000, /* Layer I */
- 256000, 288000, 320000, 352000, 384000, 416000, 448000 },
- { 0, 32000, 48000, 56000, 64000, 80000, 96000, 112000, /* Layer II */
- 128000, 160000, 192000, 224000, 256000, 320000, 384000 },
- { 0, 32000, 40000, 48000, 56000, 64000, 80000, 96000, /* Layer III */
- 112000, 128000, 160000, 192000, 224000, 256000, 320000 },
-
- /* MPEG-2 LSF */
- { 0, 32000, 48000, 56000, 64000, 80000, 96000, 112000, /* Layer I */
- 128000, 144000, 160000, 176000, 192000, 224000, 256000 },
- { 0, 8000, 16000, 24000, 32000, 40000, 48000, 56000, /* Layers */
- 64000, 80000, 96000, 112000, 128000, 144000, 160000 } /* II & III */
-};
-
-static
-unsigned int const samplerate_table[3] = { 44100, 48000, 32000 };
-
-static
-int (*const decoder_table[3])(struct mad_stream *, struct mad_frame *) = {
- mad_layer_I,
- mad_layer_II,
- mad_layer_III
-};
-
-/*
- * NAME: header->init()
- * DESCRIPTION: initialize header struct
- */
-void mad_header_init(struct mad_header *header)
-{
- header->layer = 0;
- header->mode = 0;
- header->mode_extension = 0;
- header->emphasis = 0;
-
- header->bitrate = 0;
- header->samplerate = 0;
-
- header->crc_check = 0;
- header->crc_target = 0;
-
- header->flags = 0;
- header->private_bits = 0;
-
- header->duration = mad_timer_zero;
-}
-
-/*
- * NAME: frame->init()
- * DESCRIPTION: initialize frame struct
- */
-void mad_frame_init(struct mad_frame *frame)
-{
- mad_header_init(&frame->header);
-
- frame->options = 0;
-
- frame->overlap = 0;
- mad_frame_mute(frame);
-}
-
-/*
- * NAME: frame->finish()
- * DESCRIPTION: deallocate any dynamic memory associated with frame
- */
-void mad_frame_finish(struct mad_frame *frame)
-{
- mad_header_finish(&frame->header);
-
- if (frame->overlap) {
- free(frame->overlap);
- frame->overlap = 0;
- }
-}
-
-/*
- * NAME: decode_header()
- * DESCRIPTION: read header data and following CRC word
- */
-static
-int decode_header(struct mad_header *header, struct mad_stream *stream)
-{
- unsigned int index;
-
- header->flags = 0;
- header->private_bits = 0;
-
- /* header() */
-
- /* syncword */
- mad_bit_skip(&stream->ptr, 11);
-
- /* MPEG 2.5 indicator (really part of syncword) */
- if (mad_bit_read(&stream->ptr, 1) == 0)
- header->flags |= MAD_FLAG_MPEG_2_5_EXT;
-
- /* ID */
- if (mad_bit_read(&stream->ptr, 1) == 0)
- header->flags |= MAD_FLAG_LSF_EXT;
- else if (header->flags & MAD_FLAG_MPEG_2_5_EXT) {
- stream->error = MAD_ERROR_LOSTSYNC;
- return -1;
- }
-
- /* layer */
- header->layer = 4 - mad_bit_read(&stream->ptr, 2);
-
- if (header->layer == 4) {
- stream->error = MAD_ERROR_BADLAYER;
- return -1;
- }
-
- /* protection_bit */
- if (mad_bit_read(&stream->ptr, 1) == 0) {
- header->flags |= MAD_FLAG_PROTECTION;
- header->crc_check = mad_bit_crc(stream->ptr, 16, 0xffff);
- }
-
- /* bitrate_index */
- index = mad_bit_read(&stream->ptr, 4);
-
- if (index == 15) {
- stream->error = MAD_ERROR_BADBITRATE;
- return -1;
- }
-
- if (header->flags & MAD_FLAG_LSF_EXT)
- header->bitrate = bitrate_table[3 + (header->layer >> 1)][index];
- else
- header->bitrate = bitrate_table[header->layer - 1][index];
-
- /* sampling_frequency */
- index = mad_bit_read(&stream->ptr, 2);
-
- if (index == 3) {
- stream->error = MAD_ERROR_BADSAMPLERATE;
- return -1;
- }
-
- header->samplerate = samplerate_table[index];
-
- if (header->flags & MAD_FLAG_LSF_EXT) {
- header->samplerate /= 2;
-
- if (header->flags & MAD_FLAG_MPEG_2_5_EXT)
- header->samplerate /= 2;
- }
-
- /* padding_bit */
- if (mad_bit_read(&stream->ptr, 1))
- header->flags |= MAD_FLAG_PADDING;
-
- /* private_bit */
- if (mad_bit_read(&stream->ptr, 1))
- header->private_bits |= MAD_PRIVATE_HEADER;
-
- /* mode */
- header->mode = 3 - mad_bit_read(&stream->ptr, 2);
-
- /* mode_extension */
- header->mode_extension = mad_bit_read(&stream->ptr, 2);
-
- /* copyright */
- if (mad_bit_read(&stream->ptr, 1))
- header->flags |= MAD_FLAG_COPYRIGHT;
-
- /* original/copy */
- if (mad_bit_read(&stream->ptr, 1))
- header->flags |= MAD_FLAG_ORIGINAL;
-
- /* emphasis */
- header->emphasis = mad_bit_read(&stream->ptr, 2);
-
-# if defined(OPT_STRICT)
- /*
- * ISO/IEC 11172-3 says this is a reserved emphasis value, but
- * streams exist which use it anyway. Since the value is not important
- * to the decoder proper, we allow it unless OPT_STRICT is defined.
- */
- if (header->emphasis == MAD_EMPHASIS_RESERVED) {
- stream->error = MAD_ERROR_BADEMPHASIS;
- return -1;
- }
-# endif
-
- /* error_check() */
-
- /* crc_check */
- if (header->flags & MAD_FLAG_PROTECTION)
- header->crc_target = mad_bit_read(&stream->ptr, 16);
-
- return 0;
-}
-
-/*
- * NAME: free_bitrate()
- * DESCRIPTION: attempt to discover the bitstream's free bitrate
- */
-static
-int free_bitrate(struct mad_stream *stream, struct mad_header const *header)
-{
- struct mad_bitptr keep_ptr;
- unsigned long rate = 0;
- unsigned int pad_slot, slots_per_frame;
- unsigned char const *ptr = 0;
-
- keep_ptr = stream->ptr;
-
- pad_slot = (header->flags & MAD_FLAG_PADDING) ? 1 : 0;
- slots_per_frame = (header->layer == MAD_LAYER_III &&
- (header->flags & MAD_FLAG_LSF_EXT)) ? 72 : 144;
-
- while (mad_stream_sync(stream) == 0) {
- struct mad_stream peek_stream;
- struct mad_header peek_header;
-
- peek_stream = *stream;
- peek_header = *header;
-
- if (decode_header(&peek_header, &peek_stream) == 0 &&
- peek_header.layer == header->layer &&
- peek_header.samplerate == header->samplerate) {
- unsigned int N;
-
- ptr = mad_bit_nextbyte(&stream->ptr);
-
- N = ptr - stream->this_frame;
-
- if (header->layer == MAD_LAYER_I) {
- rate = (unsigned long) header->samplerate *
- (N - 4 * pad_slot + 4) / 48 / 1000;
- }
- else {
- rate = (unsigned long) header->samplerate *
- (N - pad_slot + 1) / slots_per_frame / 1000;
- }
-
- if (rate >= 8)
- break;
- }
-
- mad_bit_skip(&stream->ptr, 8);
- }
-
- stream->ptr = keep_ptr;
-
- if (rate < 8 || (header->layer == MAD_LAYER_III && rate > 640)) {
- stream->error = MAD_ERROR_LOSTSYNC;
- return -1;
- }
-
- stream->freerate = rate * 1000;
-
- return 0;
-}
-
-/*
- * NAME: header->decode()
- * DESCRIPTION: read the next frame header from the stream
- */
-int mad_header_decode(struct mad_header *header, struct mad_stream *stream)
-{
- register unsigned char const *ptr, *end;
- unsigned int pad_slot, N;
-
- ptr = stream->next_frame;
- end = stream->bufend;
-
- if (ptr == 0) {
- stream->error = MAD_ERROR_BUFPTR;
- goto fail;
- }
-
- /* stream skip */
- if (stream->skiplen) {
- if (!stream->sync)
- ptr = stream->this_frame;
-
- if (end - ptr < stream->skiplen) {
- stream->skiplen -= end - ptr;
- stream->next_frame = end;
-
- stream->error = MAD_ERROR_BUFLEN;
- goto fail;
- }
-
- ptr += stream->skiplen;
- stream->skiplen = 0;
-
- stream->sync = 1;
- }
-
- sync:
- /* synchronize */
- if (stream->sync) {
- if (end - ptr < MAD_BUFFER_GUARD) {
- stream->next_frame = ptr;
-
- stream->error = MAD_ERROR_BUFLEN;
- goto fail;
- }
- else if (!(ptr[0] == 0xff && (ptr[1] & 0xe0) == 0xe0)) {
- /* mark point where frame sync word was expected */
- stream->this_frame = ptr;
- stream->next_frame = ptr + 1;
-
- stream->error = MAD_ERROR_LOSTSYNC;
- goto fail;
- }
- }
- else {
- mad_bit_init(&stream->ptr, ptr);
-
- if (mad_stream_sync(stream) == -1) {
- if (end - stream->next_frame >= MAD_BUFFER_GUARD)
- stream->next_frame = end - MAD_BUFFER_GUARD;
-
- stream->error = MAD_ERROR_BUFLEN;
- goto fail;
- }
-
- ptr = mad_bit_nextbyte(&stream->ptr);
- }
-
- /* begin processing */
- stream->this_frame = ptr;
- stream->next_frame = ptr + 1; /* possibly bogus sync word */
-
- mad_bit_init(&stream->ptr, stream->this_frame);
-
- if (decode_header(header, stream) == -1)
- goto fail;
-
- /* calculate frame duration */
- mad_timer_set(&header->duration, 0,
- 32 * MAD_NSBSAMPLES(header), header->samplerate);
-
- /* calculate free bit rate */
- if (header->bitrate == 0) {
- if ((stream->freerate == 0 || !stream->sync ||
- (header->layer == MAD_LAYER_III && stream->freerate > 640000)) &&
- free_bitrate(stream, header) == -1)
- goto fail;
-
- header->bitrate = stream->freerate;
- header->flags |= MAD_FLAG_FREEFORMAT;
- }
-
- /* calculate beginning of next frame */
- pad_slot = (header->flags & MAD_FLAG_PADDING) ? 1 : 0;
-
- if (header->layer == MAD_LAYER_I)
- N = ((12 * header->bitrate / header->samplerate) + pad_slot) * 4;
- else {
- unsigned int slots_per_frame;
-
- slots_per_frame = (header->layer == MAD_LAYER_III &&
- (header->flags & MAD_FLAG_LSF_EXT)) ? 72 : 144;
-
- N = (slots_per_frame * header->bitrate / header->samplerate) + pad_slot;
- }
-
- /* verify there is enough data left in buffer to decode this frame */
- if (N + MAD_BUFFER_GUARD > end - stream->this_frame) {
- stream->next_frame = stream->this_frame;
-
- stream->error = MAD_ERROR_BUFLEN;
- goto fail;
- }
-
- stream->next_frame = stream->this_frame + N;
-
- if (!stream->sync) {
- /* check that a valid frame header follows this frame */
-
- ptr = stream->next_frame;
- if (!(ptr[0] == 0xff && (ptr[1] & 0xe0) == 0xe0)) {
- ptr = stream->next_frame = stream->this_frame + 1;
- goto sync;
- }
-
- stream->sync = 1;
- }
-
- header->flags |= MAD_FLAG_INCOMPLETE;
-
- return 0;
-
- fail:
- stream->sync = 0;
-
- return -1;
-}
-
-/*
- * NAME: frame->decode()
- * DESCRIPTION: decode a single frame from a bitstream
- */
-int mad_frame_decode(struct mad_frame *frame, struct mad_stream *stream)
-{
- frame->options = stream->options;
-
- /* header() */
- /* error_check() */
-
- if (!(frame->header.flags & MAD_FLAG_INCOMPLETE) &&
- mad_header_decode(&frame->header, stream) == -1)
- goto fail;
-
- /* audio_data() */
-
- frame->header.flags &= ~MAD_FLAG_INCOMPLETE;
-
- if (decoder_table[frame->header.layer - 1](stream, frame) == -1) {
- if (!MAD_RECOVERABLE(stream->error))
- stream->next_frame = stream->this_frame;
-
- goto fail;
- }
-
- /* ancillary_data() */
-
- if (frame->header.layer != MAD_LAYER_III) {
- struct mad_bitptr next_frame;
-
- mad_bit_init(&next_frame, stream->next_frame);
-
- stream->anc_ptr = stream->ptr;
- stream->anc_bitlen = mad_bit_length(&stream->ptr, &next_frame);
-
- mad_bit_finish(&next_frame);
- }
-
- return 0;
-
- fail:
- stream->anc_bitlen = 0;
- return -1;
-}
-
-/*
- * NAME: frame->mute()
- * DESCRIPTION: zero all subband values so the frame becomes silent
- */
-void mad_frame_mute(struct mad_frame *frame)
-{
- unsigned int s, sb;
-
- for (s = 0; s < 36; ++s) {
- for (sb = 0; sb < 32; ++sb) {
- frame->sbsample[0][s][sb] =
- frame->sbsample[1][s][sb] = 0;
- }
- }
-
- if (frame->overlap) {
- for (s = 0; s < 18; ++s) {
- for (sb = 0; sb < 32; ++sb) {
- (*frame->overlap)[0][sb][s] =
- (*frame->overlap)[1][sb][s] = 0;
- }
- }
- }
-}
-
-# ifdef _MSC_VER
-# pragma warning(pop)
-# endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-19 15:32:45 +0000