diff options
Diffstat (limited to 'faad2/src/common/faad/aacinfo.c')
| -rw-r--r-- | faad2/src/common/faad/aacinfo.c | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/faad2/src/common/faad/aacinfo.c b/faad2/src/common/faad/aacinfo.c new file mode 100644 index 0000000..1cfbab2 --- /dev/null +++ b/faad2/src/common/faad/aacinfo.c @@ -0,0 +1,372 @@ +/*
+** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
+** Copyright (C) 2003 M. Bakker, Ahead Software AG, http://www.nero.com
+**
+** 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.
+**
+** Any non-GPL usage of this software or parts of this software is strictly
+** forbidden.
+**
+** Commercial non-GPL licensing of this software is possible.
+** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
+**
+** $Id: aacinfo.c,v 1.4 2003/07/29 08:20:11 menno Exp $
+**/
+
+#ifdef _WIN32
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#endif
+#include <malloc.h>
+#include "filestream.h"
+#include "aacinfo.h"
+
+#define ADIF_MAX_SIZE 30 /* Should be enough */
+#define ADTS_MAX_SIZE 10 /* Should be enough */
+
+static int sample_rates[] = {96000,88200,64000,48000,44100,32000,24000,22050,16000,12000,11025,8000};
+
+static int read_ADIF_header(FILE_STREAM *file, faadAACInfo *info)
+{
+ int bitstream;
+ unsigned char buffer[ADIF_MAX_SIZE];
+ int skip_size = 0;
+ int sf_idx;
+
+ /* Get ADIF header data */
+ info->headertype = 1;
+
+ if(read_buffer_filestream(file, buffer, ADIF_MAX_SIZE) < 0)
+ return -1;
+
+ /* copyright string */
+ if(buffer[0] & 0x80)
+ skip_size += 9; /* skip 9 bytes */
+
+ bitstream = buffer[0 + skip_size] & 0x10;
+ info->bitrate = ((unsigned int)(buffer[0 + skip_size] & 0x0F)<<19)|
+ ((unsigned int)buffer[1 + skip_size]<<11)|
+ ((unsigned int)buffer[2 + skip_size]<<3)|
+ ((unsigned int)buffer[3 + skip_size] & 0xE0);
+
+ if (bitstream == 0)
+ {
+ info->object_type = ((buffer[6 + skip_size]&0x01)<<1)|((buffer[7 + skip_size]&0x80)>>7);
+ sf_idx = (buffer[7 + skip_size]&0x78)>>3;
+ } else {
+ info->object_type = (buffer[4 + skip_size] & 0x18)>>3;
+ sf_idx = ((buffer[4 + skip_size] & 0x07)<<1)|((buffer[5 + skip_size] & 0x80)>>7);
+ }
+ info->sampling_rate = sample_rates[sf_idx];
+
+ return 0;
+}
+
+static int read_ADTS_header(FILE_STREAM *file, faadAACInfo *info,
+ unsigned long **seek_table, int *seek_table_len,
+ int tagsize, int no_seek_table)
+{
+ /* Get ADTS header data */
+ unsigned char buffer[ADTS_MAX_SIZE];
+ int frames, framesinsec=0, t_framelength = 0, frame_length, sr_idx, ID;
+ int second = 0, pos;
+ int i;
+ float frames_per_sec = 0;
+ unsigned long bytes;
+ unsigned long *tmp_seek_table = NULL;
+
+ info->headertype = 2;
+
+ /* Read all frames to ensure correct time and bitrate */
+ for(frames=0; /* */; frames++, framesinsec++)
+ {
+ /* If streaming, only go until we hit 5 seconds worth */
+ if(file->http)
+ {
+ if(frames >= 43 * 5)
+ {
+ break;
+ }
+ }
+
+ pos = tell_filestream(file);
+
+ /* 12 bit SYNCWORD */
+ bytes = read_buffer_filestream(file, buffer, ADTS_MAX_SIZE);
+
+ if(bytes != ADTS_MAX_SIZE)
+ {
+ /* Bail out if no syncword found */
+ break;
+ }
+
+ /* check syncword */
+ if (!((buffer[0] == 0xFF)&&((buffer[1] & 0xF6) == 0xF0)))
+ break;
+
+ if(!frames)
+ {
+ /* fixed ADTS header is the same for every frame, so we read it only once */
+ /* Syncword found, proceed to read in the fixed ADTS header */
+ ID = buffer[1] & 0x08;
+ info->object_type = (buffer[2]&0xC0)>>6;
+ sr_idx = (buffer[2]&0x3C)>>2;
+ info->channels = ((buffer[2]&0x01)<<2)|((buffer[3]&0xC0)>>6);
+
+ frames_per_sec = sample_rates[sr_idx] / 1024.f;
+ }
+
+ /* ...and the variable ADTS header */
+ if (ID == 0) {
+ info->version = 4;
+ } else { /* MPEG-2 */
+ info->version = 2;
+ }
+ frame_length = ((((unsigned int)buffer[3] & 0x3)) << 11)
+ | (((unsigned int)buffer[4]) << 3) | (buffer[5] >> 5);
+
+ t_framelength += frame_length;
+
+ if(!file->http)
+ {
+ if(framesinsec == 43)
+ framesinsec = 0;
+
+ if(framesinsec == 0 && seek_table_len)
+ {
+ tmp_seek_table = (unsigned long *) realloc(tmp_seek_table, (second + 1) * sizeof(unsigned long));
+ tmp_seek_table[second] = pos;
+ }
+ if(framesinsec == 0)
+ second++;
+ }
+
+ /* NOTE: While simply skipping ahead by reading may seem to be more work than seeking,
+ it is actually much faster, and keeps compatibility with streaming */
+ for(i=0; i < frame_length - ADTS_MAX_SIZE; i++)
+ {
+ if(read_byte_filestream(file) < 0)
+ break;
+ }
+ }
+
+ if(seek_table_len)
+ {
+ *seek_table_len = second;
+ *seek_table = tmp_seek_table;
+ }
+
+ info->sampling_rate = sample_rates[sr_idx];
+ info->bitrate = (int)(((t_framelength / frames) * (info->sampling_rate/1024.0)) +0.5)*8;
+
+ if(file->http)
+ {
+ /* Since we only use 5 seconds of aac data to get a rough bitrate, we must use a different
+ method of calculating the overall length */
+ if(filelength_filestream(file))
+ {
+ info->length = (int)((filelength_filestream(file)/(((info->bitrate*8)/1024)*16))*1000);
+ }
+ else
+ {
+ /* Since the server didnt tell us how long the file is,
+ we have no way of determining length */
+ info->length = 0;
+ }
+ }
+ else
+ {
+ info->length = (int)((float)(frames/frames_per_sec))*1000;
+ }
+
+ return 0;
+}
+
+int get_AAC_format(char *filename, faadAACInfo *info,
+ unsigned long **seek_table, int *seek_table_len,
+ int no_seek_table)
+{
+ unsigned long tagsize;
+ FILE_STREAM *file;
+ char buffer[10];
+ unsigned long file_len;
+ unsigned char adxx_id[5];
+ unsigned long tmp;
+
+ memset(info, 0, sizeof(faadAACInfo));
+
+ file = open_filestream(filename);
+
+ if(file == NULL)
+ return -1;
+
+ file_len = filelength_filestream(file);
+
+ /* Skip the tag, if it's there */
+ tmp = read_buffer_filestream(file, buffer, 10);
+
+ if (StringComp(buffer, "ID3", 3) == 0)
+ {
+ unsigned int i;
+
+ /* high bit is not used */
+ tagsize = (buffer[6] << 21) | (buffer[7] << 14) |
+ (buffer[8] << 7) | (buffer[9] << 0);
+
+ for(i=0; i < tagsize; i++)
+ if(read_byte_filestream(file) < 0)
+ return -1;
+
+ tagsize += 10;
+ }
+ else
+ {
+ tagsize = 0;
+
+ /* Simple hack to reset to the beginning */
+ file->buffer_offset = 0;
+ file->file_offset = 0;
+ }
+
+ if(file_len)
+ file_len -= tagsize;
+
+ tmp = read_buffer_filestream(file, adxx_id, 2);
+ //seek_filestream(file, tagsize, FILE_BEGIN);
+
+ adxx_id[5-1] = 0;
+ info->length = 0;
+
+ /* Determine the header type of the file, check the first two bytes */
+ if(StringComp(adxx_id, "AD", 2) == 0)
+ {
+ /* We think its an ADIF header, but check the rest just to make sure */
+ tmp = read_buffer_filestream(file, adxx_id + 2, 2);
+
+ if(StringComp(adxx_id, "ADIF", 4) == 0)
+ {
+ read_ADIF_header(file, info);
+ }
+ }
+ else
+ {
+ /* No ADIF, check for ADTS header */
+ if ((adxx_id[0] == 0xFF)&&((adxx_id[1] & 0xF6) == 0xF0))
+ {
+ /* ADTS header located */
+ /* Since this routine must work for streams, we can't use the seek function to go backwards, thus
+ we have to use a quick hack as seen below to go back where we need to. */
+
+ if(file->buffer_offset >= 2)
+ {
+ // simple seeking hack, though not really safe, the probability of it causing a problem is low.
+ file->buffer_offset -= 2;
+ file->file_offset -= 2;
+ }
+
+ read_ADTS_header(file, info, seek_table, seek_table_len, tagsize,
+ no_seek_table);
+ }
+ else
+ {
+ /* Unknown/headerless AAC file, assume format: */
+ info->version = 2;
+ info->bitrate = 128000;
+ info->sampling_rate = 44100;
+ info->channels = 2;
+ info->headertype = 0;
+ info->object_type = 1;
+ }
+ }
+
+ close_filestream(file);
+
+ return 0;
+}
+
+int StringComp(char const *str1, char const *str2, unsigned long len)
+{
+ signed int c1 = 0, c2 = 0;
+
+ while (len--) {
+ c1 = *str1++;
+ c2 = *str2++;
+
+ if (c1 == 0 || c1 != c2)
+ break;
+ }
+
+ return c1 - c2;
+}
+
+#ifdef TEST
+/* Program to test aacinfo functionality */
+
+#include <stdio.h>
+
+void main(int argc, char *argv[])
+{
+ faadAACInfo info;
+ unsigned long *seek_table = NULL;
+ int seek_table_len = 0;
+ char *header, *object;
+
+ if (argc < 2)
+ {
+ fprintf(stderr, "USAGE: aacinfo aacfile.aac\n");
+ return;
+ }
+
+ get_AAC_format(argv[1], &info, &seek_table, &seek_table_len, 0);
+
+ fprintf(stdout, "MPEG version: %d\n", info.version);
+ fprintf(stdout, "channels: %d\n", info.channels);
+ fprintf(stdout, "sampling_rate: %d\n", info.sampling_rate);
+ fprintf(stdout, "bitrate: %d\n", info.bitrate);
+ fprintf(stdout, "length: %.3f\n", (float)info.length/1000.0);
+
+ switch (info.object_type)
+ {
+ case 0:
+ object = "MAIN";
+ break;
+ case 1:
+ object = "LC";
+ break;
+ case 2:
+ object = "SSR";
+ break;
+ case 3:
+ object = "LTP";
+ break;
+ }
+ fprintf(stdout, "object_type: %s\n", object);
+
+ switch (info.headertype)
+ {
+ case 0:
+ header = "RAW";
+ break;
+ case 1:
+ header = "ADIF";
+ break;
+ case 2:
+ header = "ADTS";
+ break;
+ }
+ fprintf(stdout, "headertype: %s\n", header);
+}
+
+#endif
\ No newline at end of file |