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