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