aac_afh.c

   1 /*
   2  * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     This program is distributed in the hope that it will be useful,
  10  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *     GNU General Public License for more details.
  13  *
  14  *     You should have received a copy of the GNU General Public License
  15  *     along with this program; if not, write to the Free Software
  16  *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  17  */
  18 /*
  19  * based in parts on libfaad, Copyright (C) 2003-2005 M. Bakker,
  20  * Ahead Software AG
  21  */
  22
  23 /** \file aac_afh.c para_server's aac audio format handler */
  24
  25 #include "server.cmdline.h"
  26 #include "server.h"
  27 #include "afs.h"
  28 #include "error.h"
  29 #include "string.h"
  30 #include "aac.h"
  31 #include "fd.h"
  32
  33 /* must be big enough to hold header */
  34 #define DEFAULT_INBUF_SIZE 65536
  35
  36 static FILE *infile;
  37 static int inbuf_size;
  38 static unsigned char *inbuf;
  39 static size_t inbuf_len;
  40 struct audio_format_handler *af;
  41 static size_t num_chunks;
  42 static size_t entry;
  43
  44 static size_t *chunk_table;
  45 NeAACDecHandle handle;
  46
  47 static void aac_close_audio_file(void)
  48 {
  49         if (!infile)
  50                 return;
  51         fclose(infile);
  52         infile = NULL;
  53 }
  54
  55 static int aac_find_stsz(unsigned char *buf, unsigned buflen, size_t *skip)
  56 {
  57         int i;
  58
  59         for (i = 0; i + 16 < buflen; i++) {
  60                 unsigned char *p = buf + i;
  61                 unsigned sample_count, sample_size;
  62
  63                 if (p[0] != 's' || p[1] != 't' || p[2] != 's' || p[3] != 'z')
  64                         continue;
  65                 PARA_INFO_LOG("found stsz@%d\n", i);
  66                 i += 8;
  67                 sample_size = aac_read_int32(buf + i);
  68                 PARA_INFO_LOG("sample size: %d\n", sample_size);
  69                 i += 4;
  70                 sample_count = aac_read_int32(buf + i);
  71                 i += 4;
  72                 PARA_INFO_LOG("sample count: %d\n", sample_count);
  73                 *skip = i;
  74                 return sample_count;
  75         }
  76         PARA_WARNING_LOG("stsz not found, buflen: %d\n", buflen);
  77         return -E_STSZ;
  78 }
  79
  80 static int read_chunk_table(size_t skip)
  81 {
  82         int ret, i;
  83         size_t sum = 0;
  84
  85         for (;;) {
  86                 ret = aac_find_stsz(inbuf, inbuf_len, &skip);
  87                 if (ret >= 0)
  88                         break;
  89                 ret = read(fileno(infile), inbuf, inbuf_size);
  90                 if (ret <= 0)
  91                         return -E_AAC_READ;
  92                 PARA_INFO_LOG("next buffer: %d bytes\n", ret);
  93         }
  94         num_chunks = ret;
  95         PARA_INFO_LOG("sz table has %zu entries\n", num_chunks);
  96         free(chunk_table);
  97         chunk_table = para_malloc(num_chunks * sizeof(size_t));
  98         for (i = 0; i < num_chunks; i++) {
  99                 if (skip + 4 > inbuf_len) {
 100                         skip = inbuf_len - skip;
 101                         memmove(inbuf, inbuf + inbuf_len - skip, skip);
 102                         ret = read(fileno(infile), inbuf + skip, inbuf_size - skip);
 103                         if (ret <= 0)
 104                                 return -E_AAC_READ;
 105                         inbuf_len = ret + skip;
 106                         skip = 0;
 107                         PARA_INFO_LOG("next buffer: %zu bytes\n", inbuf_len);
 108                 }
 109                 sum += aac_read_int32(inbuf + skip);
 110                 chunk_table[i] = sum;
 111                 skip += 4;
 112                 if (i < 10 || i + 10 > num_chunks)
 113                         PARA_DEBUG_LOG("offset #%d: %zu\n", i, chunk_table[i]);
 114         }
 115         return 1;
 116
 117 }
 118
 119 long unsigned aac_set_chunk_tv(mp4AudioSpecificConfig *mp4ASC)
 120 {
 121         float tmp = mp4ASC->sbr_present_flag == 1? 2047 : 1023,
 122                 ms = 1000.0 * num_chunks * tmp / mp4ASC->samplingFrequency;
 123         struct timeval total;
 124
 125         ms2tv(ms, &total);
 126         tv_divide(num_chunks, &total, &af->chunk_tv);
 127         PARA_INFO_LOG("%luHz, %fs (%zd x %lums)\n",
 128                 mp4ASC->samplingFrequency, ms / 1000,
 129                 num_chunks, tv2ms(&af->chunk_tv));
 130         return ms / 1000;
 131 }
 132
 133 /*
 134  * Init m4a file and write some tech data to given pointers.
 135  */
 136 static int aac_get_file_info(FILE *file, char *info_str, long unsigned *frames,
 137         int *seconds)
 138 {
 139         int ret, decoder_len;
 140         size_t skip;
 141         unsigned long rate = 0;
 142         unsigned char channels = 0;
 143         mp4AudioSpecificConfig mp4ASC;
 144
 145         free(inbuf);
 146         inbuf_size = DEFAULT_INBUF_SIZE;
 147         inbuf = para_malloc(inbuf_size);
 148         infile = file;
 149
 150         ret = read(fileno(infile), inbuf, inbuf_size);
 151         if (ret <= 0)
 152                 return -E_AAC_READ;
 153         inbuf_len = ret;
 154         ret = aac_find_esds(inbuf, inbuf_len, &skip);
 155         if (ret < 0)
 156                 return ret;
 157         decoder_len = ret;
 158         handle = aac_open();
 159         ret = NeAACDecInit(handle, inbuf + skip,
 160                 decoder_len, &rate, &channels);
 161         if (ret < 0)
 162                 return -E_AACDEC_INIT;
 163         skip += ret;
 164         PARA_INFO_LOG("rate: %lu, channels: %d\n", rate, channels);
 165         ret = NeAACDecAudioSpecificConfig(inbuf + skip, inbuf_len - skip,
 166                 &mp4ASC);
 167         if (ret < 0)
 168                 return -E_MP4ASC;
 169         ret = read_chunk_table(skip);
 170         if (ret < 0)
 171                 return ret;
 172         *frames = num_chunks;
 173         *seconds = aac_set_chunk_tv(&mp4ASC);
 174         for (;;) {
 175                 ret = aac_find_entry_point(inbuf, inbuf_len, &skip);
 176                 if (ret >= 0)
 177                         break;
 178                 ret = read(fileno(infile), inbuf, inbuf_size);
 179                 if (ret <= 0)
 180                         return -E_AAC_READ;
 181                 PARA_INFO_LOG("next buffer: %d bytes\n", ret);
 182         }
 183         entry = ret;
 184         sprintf(info_str, "audio_file_info1:%zu x %lums\n"
 185                 "audio_file_info2:\n"
 186                 "audio_file_info3:\n",
 187                 num_chunks,
 188                 tv2ms(&af->chunk_tv));
 189         return 1;
 190 }
 191
 192 /*
 193  * Simple stream reposition routine
 194  */
 195 static int aac_reposition_stream(long unsigned request)
 196 {
 197         return 1;
 198 //      return -E_AAC_REPOS;
 199 }
 200
 201 static char *aac_read_chunk(long unsigned current_chunk, ssize_t *len)
 202 {
 203         int ret;
 204         size_t pos;
 205
 206         *len = 0;
 207         if (current_chunk >= num_chunks)
 208                 return NULL;
 209         if (!current_chunk) {
 210                 *len = chunk_table[0];
 211                 pos = entry;
 212         } else {
 213                 *len = chunk_table[current_chunk] - chunk_table[current_chunk - 1];
 214                 pos = entry + chunk_table[current_chunk - 1];
 215         }
 216         if (inbuf_size < *len) {
 217                 inbuf = para_realloc(inbuf, *len);
 218                 inbuf_size = *len;
 219         }
 220 //      PARA_DEBUG_LOG("reading chunk #%lu@%zd (%zd bytes)\n", current_chunk,
 221 //              pos, *len);
 222         ret = fseek(infile, pos, SEEK_SET);
 223         if (ret < 0)
 224                 return NULL;
 225         ret = para_fread(inbuf, *len, 1, infile);
 226         if (ret != *len)
 227                 return NULL;
 228 //      PARA_DEBUG_LOG("ret: %d, inbuf[0]: %lx - %lx\n", ret, (long unsigned) inbuf[0],
 229 //              (long unsigned) inbuf[4]);
 230         return (char *)inbuf;
 231 }
 232
 233 static const char* aac_suffixes[] = {"m4a", NULL};
 234 /** the init function of the aac audio format handler */
 235 void aac_afh_init(struct audio_format_handler *p)
 236 {
 237         af = p;
 238         af->reposition_stream = aac_reposition_stream;
 239         af->get_file_info = aac_get_file_info,
 240         af->read_chunk = aac_read_chunk;
 241         af->close_audio_file = aac_close_audio_file;
 242         af->get_header_info = NULL;
 243         tv_scale(3, &af->chunk_tv, &af->eof_tv);
 244         af->suffixes = aac_suffixes;
 245 }