aac_afh.c

   1 /*
   2  * Copyright (C) 2006-2007 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 "vss.h"
  28 #include "error.h"
  29 #include "string.h"
  30 #include "aac.h"
  31 #include "fd.h"
  32
  33 /** size of the input buffer, must be big enough to hold header */
  34 #define AAC_INBUF_SIZE 65536
  35
  36 static FILE *infile;
  37 static unsigned char *inbuf;
  38 static size_t inbuf_len;
  39
  40 static void aac_close_audio_file(void)
  41 {
  42         if (!infile)
  43                 return;
  44         fclose(infile);
  45         infile = NULL;
  46 }
  47
  48 static int aac_find_stsz(unsigned char *buf, unsigned buflen, size_t *skip)
  49 {
  50         int i;
  51
  52         for (i = 0; i + 16 < buflen; i++) {
  53                 unsigned char *p = buf + i;
  54                 unsigned sample_count, sample_size;
  55
  56                 if (p[0] != 's' || p[1] != 't' || p[2] != 's' || p[3] != 'z')
  57                         continue;
  58                 PARA_INFO_LOG("found stsz@%d\n", i);
  59                 i += 8;
  60                 sample_size = aac_read_int32(buf + i);
  61                 PARA_INFO_LOG("sample size: %d\n", sample_size);
  62                 i += 4;
  63                 sample_count = aac_read_int32(buf + i);
  64                 i += 4;
  65                 PARA_INFO_LOG("sample count: %d\n", sample_count);
  66                 *skip = i;
  67                 return sample_count;
  68         }
  69         PARA_WARNING_LOG("stsz not found, buflen: %d\n", buflen);
  70         return -E_STSZ;
  71 }
  72
  73 static int read_chunk_table(struct audio_format_info *afi, size_t skip)
  74 {
  75         int ret, i;
  76         size_t sum = 0;
  77
  78         for (;;) {
  79                 ret = aac_find_stsz(inbuf, inbuf_len, &skip);
  80                 if (ret >= 0)
  81                         break;
  82                 ret = read(fileno(infile), inbuf, AAC_INBUF_SIZE);
  83                 if (ret <= 0)
  84                         return -E_AAC_READ;
  85                 inbuf_len = ret;
  86                 PARA_INFO_LOG("next buffer: %d bytes\n", ret);
  87         }
  88         afi->chunks_total = ret;
  89         PARA_INFO_LOG("sz table has %lu entries\n", afi->chunks_total);
  90         afi->chunk_table = para_malloc((afi->chunks_total + 1) * sizeof(size_t));
  91         for (i = 1; i <= afi->chunks_total; i++) {
  92                 if (skip + 4 > inbuf_len) {
  93                         skip = inbuf_len - skip;
  94                         memmove(inbuf, inbuf + inbuf_len - skip, skip);
  95                         ret = read(fileno(infile), inbuf + skip,
  96                                 AAC_INBUF_SIZE - skip);
  97                         if (ret <= 0)
  98                                 return -E_AAC_READ;
  99                         inbuf_len = ret + skip;
 100                         skip = 0;
 101                         PARA_INFO_LOG("next buffer: %zu bytes\n", inbuf_len);
 102                 }
 103                 sum += aac_read_int32(inbuf + skip);
 104                 afi->chunk_table[i] = sum;
 105                 skip += 4;
 106                 if (i < 10 || i + 10 > afi->chunks_total)
 107                         PARA_DEBUG_LOG("offset #%d: %zu\n", i, afi->chunk_table[i]);
 108         }
 109         return 1;
 110 }
 111
 112 static long unsigned aac_set_chunk_tv(struct audio_format_info *afi,
 113                 mp4AudioSpecificConfig *mp4ASC)
 114 {
 115         float tmp = mp4ASC->sbr_present_flag == 1? 2047 : 1023,
 116                 ms = 1000.0 * afi->chunks_total * tmp / mp4ASC->samplingFrequency;
 117         struct timeval total;
 118
 119         ms2tv(ms, &total);
 120         tv_divide(afi->chunks_total, &total, &afi->chunk_tv);
 121         PARA_INFO_LOG("%luHz, %fs (%lu x %lums)\n",
 122                 mp4ASC->samplingFrequency, ms / 1000,
 123                 afi->chunks_total, tv2ms(&afi->chunk_tv));
 124         return ms / 1000;
 125 }
 126
 127 /*
 128  * Init m4a file and write some tech data to given pointers.
 129  */
 130 static int aac_get_file_info(FILE *file, struct audio_format_info *afi)
 131 {
 132         int i, ret, decoder_len;
 133         size_t skip;
 134         unsigned long rate = 0;
 135         unsigned char channels = 0;
 136         mp4AudioSpecificConfig mp4ASC;
 137         NeAACDecHandle handle;
 138
 139         inbuf = para_malloc(AAC_INBUF_SIZE);
 140         infile = file;
 141
 142         ret = read(fileno(infile), inbuf, AAC_INBUF_SIZE);
 143         if (ret <= 0) {
 144                 ret = -E_AAC_READ;
 145                 goto out;
 146         }
 147         inbuf_len = ret;
 148         ret = aac_find_esds(inbuf, inbuf_len, &skip);
 149         if (ret < 0)
 150                 goto out;
 151         decoder_len = ret;
 152         handle = aac_open();
 153         ret = NeAACDecInit(handle, inbuf + skip, decoder_len, &rate, &channels);
 154         if (ret < 0) {
 155                 ret = -E_AACDEC_INIT;
 156                 goto out;
 157         }
 158         skip += ret;
 159         PARA_INFO_LOG("rate: %lu, channels: %d\n", rate, channels);
 160         ret = -E_MP4ASC;
 161         if (NeAACDecAudioSpecificConfig(inbuf + skip, inbuf_len - skip,
 162                         &mp4ASC) < 0)
 163                 goto out;
 164         ret = read_chunk_table(afi, skip);
 165         if (ret < 0)
 166                 goto out;
 167         afi->seconds_total = aac_set_chunk_tv(afi, &mp4ASC);
 168         for (;;) {
 169                 ret = aac_find_entry_point(inbuf, inbuf_len, &skip);
 170                 if (ret >= 0)
 171                         break;
 172                 ret = read(fileno(infile), inbuf, AAC_INBUF_SIZE);
 173                 if (ret <= 0) {
 174                         ret = -E_AAC_READ;
 175                         goto out;
 176                 }
 177                 inbuf_len = ret;
 178                 PARA_INFO_LOG("next buffer: %d bytes\n", ret);
 179         }
 180         afi->chunk_table[0] = ret;
 181         for (i = 1; i<= afi->chunks_total; i++)
 182                 afi->chunk_table[i] += ret;
 183         sprintf(afi->info_string, "audio_file_info1:%lu x %lums\n"
 184                 "audio_file_info2:\n"
 185                 "audio_file_info3:\n",
 186                 afi->chunks_total,
 187                 tv2ms(&afi->chunk_tv));
 188         tv_scale(20, &afi->chunk_tv, &afi->eof_tv);
 189         ret = 1;
 190 out:
 191         free(inbuf);
 192         return ret;
 193 }
 194
 195 static const char* aac_suffixes[] = {"m4a", "mp4", NULL};
 196 /** the init function of the aac audio format handler */
 197 void aac_afh_init(struct audio_format_handler *p)
 198 {
 199         p->get_file_info = aac_get_file_info,
 200         p->close_audio_file = aac_close_audio_file;
 201         p->suffixes = aac_suffixes;
 202 }