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         free(inbuf);
  47         inbuf = NULL;
  48 }
  49
  50 static int aac_find_stsz(unsigned char *buf, unsigned buflen, size_t *skip)
  51 {
  52         int i;
  53
  54         for (i = 0; i + 16 < buflen; i++) {
  55                 unsigned char *p = buf + i;
  56                 unsigned sample_count, sample_size;
  57
  58                 if (p[0] != 's' || p[1] != 't' || p[2] != 's' || p[3] != 'z')
  59                         continue;
  60                 PARA_INFO_LOG("found stsz@%d\n", i);
  61                 i += 8;
  62                 sample_size = aac_read_int32(buf + i);
  63                 PARA_INFO_LOG("sample size: %d\n", sample_size);
  64                 i += 4;
  65                 sample_count = aac_read_int32(buf + i);
  66                 i += 4;
  67                 PARA_INFO_LOG("sample count: %d\n", sample_count);
  68                 *skip = i;
  69                 return sample_count;
  70         }
  71         PARA_WARNING_LOG("stsz not found, buflen: %d\n", buflen);
  72         return -E_STSZ;
  73 }
  74
  75 static int read_chunk_table(struct audio_format_info *afi, size_t skip)
  76 {
  77         int ret, i;
  78         size_t sum = 0;
  79
  80         for (;;) {
  81                 ret = aac_find_stsz(inbuf, inbuf_len, &skip);
  82                 if (ret >= 0)
  83                         break;
  84                 ret = read(fileno(infile), inbuf, AAC_INBUF_SIZE);
  85                 if (ret <= 0)
  86                         return -E_AAC_READ;
  87                 PARA_INFO_LOG("next buffer: %d bytes\n", ret);
  88         }
  89         afi->chunks_total = ret;
  90         PARA_INFO_LOG("sz table has %lu entries\n", afi->chunks_total);
  91         afi->chunk_table = para_malloc((afi->chunks_total + 1) * sizeof(size_t));
  92         for (i = 1; i <= afi->chunks_total; i++) {
  93                 if (skip + 4 > inbuf_len) {
  94                         skip = inbuf_len - skip;
  95                         memmove(inbuf, inbuf + inbuf_len - skip, skip);
  96                         ret = read(fileno(infile), inbuf + skip, 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                 return -E_AAC_READ;
 145         inbuf_len = ret;
 146         ret = aac_find_esds(inbuf, inbuf_len, &skip);
 147         if (ret < 0)
 148                 return ret;
 149         decoder_len = ret;
 150         handle = aac_open();
 151         ret = NeAACDecInit(handle, inbuf + skip,
 152                 decoder_len, &rate, &channels);
 153         if (ret < 0)
 154                 return -E_AACDEC_INIT;
 155         skip += ret;
 156         PARA_INFO_LOG("rate: %lu, channels: %d\n", rate, channels);
 157         ret = NeAACDecAudioSpecificConfig(inbuf + skip, inbuf_len - skip,
 158                 &mp4ASC);
 159         if (ret < 0)
 160                 return -E_MP4ASC;
 161         ret = read_chunk_table(afi, skip);
 162         if (ret < 0)
 163                 return ret;
 164         afi->seconds_total = aac_set_chunk_tv(afi, &mp4ASC);
 165         for (;;) {
 166                 ret = aac_find_entry_point(inbuf, inbuf_len, &skip);
 167                 if (ret >= 0)
 168                         break;
 169                 ret = read(fileno(infile), inbuf, AAC_INBUF_SIZE);
 170                 if (ret <= 0)
 171                         return -E_AAC_READ;
 172                 PARA_INFO_LOG("next buffer: %d bytes\n", ret);
 173         }
 174         afi->chunk_table[0] = ret;
 175         for (i = 1; i<= afi->chunks_total; i++)
 176                 afi->chunk_table[i] += ret;
 177         sprintf(afi->info_string, "audio_file_info1:%lu x %lums\n"
 178                 "audio_file_info2:\n"
 179                 "audio_file_info3:\n",
 180                 afi->chunks_total,
 181                 tv2ms(&afi->chunk_tv));
 182         tv_scale(20, &afi->chunk_tv, &afi->eof_tv);
 183         return 1;
 184 }
 185
 186 static const char* aac_suffixes[] = {"m4a", "mp4", NULL};
 187 /** the init function of the aac audio format handler */
 188 void aac_afh_init(struct audio_format_handler *p)
 189 {
 190         p->get_file_info = aac_get_file_info,
 191         p->close_audio_file = aac_close_audio_file;
 192         p->suffixes = aac_suffixes;
 193 }