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