ogg_afh_common.c

   1 /*
   2  * Copyright (C) 2004-2013 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file ogg_afh_common.c Functions common to all ogg/ codecs. */
   8
   9 #include <ogg/ogg.h>
  10 #include <regex.h>
  11
  12 #include "para.h"
  13 #include "afh.h"
  14 #include "error.h"
  15 #include "string.h"
  16 #include "ogg_afh_common.h"
  17
  18
  19 /* Taken from decoder_example.c of libvorbis-1.2.3. */
  20 static int process_packets_2_and_3(ogg_sync_state *oss,
  21                 ogg_stream_state *stream, struct afh_info *afhi,
  22                 struct ogg_afh_callback_info *ci)
  23 {
  24         ogg_page page;
  25         ogg_packet packet;
  26         int i = 0;
  27
  28         while (i < 2) {
  29                 while (i < 2) {
  30                         int ret = ogg_sync_pageout(oss, &page);
  31                         if (ret == 0)
  32                                 break; /* Need more data */
  33                         if (ret != 1)
  34                                 continue;
  35                         /*
  36                          * We can ignore any errors here as they'll also become
  37                          * apparent at packetout.
  38                          */
  39                         ogg_stream_pagein(stream, &page);
  40                         PARA_INFO_LOG("ogg page serial: %d\n",
  41                                 ogg_page_serialno(&page));
  42                         while (i < 2) {
  43                                 ret = ogg_stream_packetout(stream, &packet);
  44                                 if (ret == 0)
  45                                         break;
  46                                 if (ret < 0)
  47                                         return -E_STREAM_PACKETOUT;
  48                                 ret = ci->packet_callback(&packet, i + 1,
  49                                         ogg_page_serialno(&page), afhi,
  50                                         ci->private_data);
  51                                 if (ret < 0)
  52                                         return ret;
  53                                 if (ret == 0) /* header complete */
  54                                         return 1;
  55                                 i++;
  56                         }
  57                 }
  58         }
  59         return 1;
  60 }
  61
  62 static int process_ogg_packets(ogg_sync_state *oss, struct afh_info *afhi,
  63                 struct ogg_afh_callback_info *ci)
  64 {
  65         ogg_packet packet;
  66         ogg_stream_state stream;
  67         ogg_page page;
  68         int ret;
  69
  70         if (ogg_sync_pageout(oss, &page) != 1)
  71                 return -E_SYNC_PAGEOUT;
  72
  73         ret = ogg_page_serialno(&page);
  74         ogg_stream_init(&stream, ret);
  75
  76         ret = -E_STREAM_PAGEIN;
  77         if (ogg_stream_pagein(&stream, &page) < 0)
  78                 goto out;
  79
  80         ret = -E_STREAM_PACKETOUT;
  81         if (ogg_stream_packetout(&stream, &packet) != 1)
  82                 goto out;
  83         ret = ci->packet_callback(&packet, 0, ogg_page_serialno(&page),
  84                 afhi, ci->private_data);
  85         if (ret < 0)
  86                 goto out;
  87         ret = process_packets_2_and_3(oss, &stream, afhi, ci);
  88         if (ret < 0)
  89                 goto out;
  90         ret = 1;
  91 out:
  92         ogg_stream_clear(&stream);
  93         return ret;
  94 }
  95
  96 static void set_chunk_tv(int frames_per_chunk, int frequency,
  97                 struct timeval *result)
  98 {
  99         uint64_t x = (uint64_t)frames_per_chunk * 1000 * 1000 / frequency;
 100
 101         result->tv_sec = x / 1000 / 1000;
 102         result->tv_usec = x % (1000 * 1000);
 103         PARA_INFO_LOG("%d frames per chunk, chunk time: %lums\n",
 104                 frames_per_chunk, tv2ms(result));
 105 }
 106
 107 /**
 108  * Pass first three ogg packets to callback and build the chunk table.
 109  *
 110  * This function extracts the first three ogg packets of the audio data
 111  * given by \a map and \a numbytes and passes each packet to the callback
 112  * defined by \a ci.
 113  *
 114  * If the packet callback indicates success and \a afhi is not \p NULL, the
 115  * chunk table is built. Chunk zero contains the first three ogg packets while
 116  * all other chunks consist of exactly one ogg page.
 117  *
 118  * \param map Audio file data.
 119  * \param numbytes The length of \a map.
 120  * \param afhi Passed to the packet callback, contains chunk table.
 121  * \param ci The callback structure.
 122  *
 123  * \return Standard.
 124  */
 125 int ogg_get_file_info(char *map, size_t numbytes, struct afh_info *afhi,
 126                 struct ogg_afh_callback_info *ci)
 127 {
 128         ogg_sync_state oss;
 129         ogg_page op;
 130         long len = numbytes;
 131         char *buf;
 132         int ret, i, j, frames_per_chunk, ct_size;
 133         long long unsigned num_frames = 0;
 134
 135         ogg_sync_init(&oss);
 136         ret = -E_OGG_SYNC;
 137         buf = ogg_sync_buffer(&oss, len);
 138         if (!buf)
 139                 goto out;
 140         memcpy(buf, map, len);
 141         ret = -E_OGG_SYNC;
 142         if (ogg_sync_wrote(&oss, len) < 0)
 143                 goto out;
 144         ret = process_ogg_packets(&oss, afhi, ci);
 145         if (ret < 0)
 146                 goto out;
 147         if (!afhi)
 148                 goto out;
 149         afhi->header_len = oss.returned;
 150         oss.returned = 0;
 151         oss.fill = numbytes;
 152         /* count ogg pages and get duration of the file */
 153         for (i = 0; ogg_sync_pageseek(&oss, &op) > 0; i++)
 154                 num_frames = ogg_page_granulepos(&op);
 155         PARA_INFO_LOG("%d pages, %llu frames\n", i, num_frames);
 156         ret = -E_OGG_EMPTY;
 157         if (i == 0)
 158                 goto out;
 159         afhi->seconds_total = num_frames / afhi->frequency;
 160         /* use roughly one page per chunk */
 161         frames_per_chunk = num_frames / i;
 162         PARA_INFO_LOG("%lu seconds, %d frames/chunk\n",
 163                 afhi->seconds_total, frames_per_chunk);
 164         ct_size = 250;
 165         afhi->chunk_table = para_malloc(ct_size * sizeof(uint32_t));
 166         afhi->chunk_table[0] = 0;
 167         afhi->chunk_table[1] = afhi->header_len;
 168         oss.returned = afhi->header_len;
 169         oss.fill = numbytes;
 170         for (j = 1; ogg_sync_pageseek(&oss, &op) > 0; /* nothing */) {
 171                 int granule = ogg_page_granulepos(&op);
 172
 173                 while (granule >= (j + 1) * frames_per_chunk) {
 174                         j++;
 175                         if (j >= ct_size) {
 176                                 ct_size *= 2;
 177                                 afhi->chunk_table = para_realloc(
 178                                         afhi->chunk_table,
 179                                         ct_size * sizeof(uint32_t));
 180                         }
 181                         afhi->chunk_table[j] = oss.returned;
 182                 }
 183         }
 184         afhi->chunks_total = j;
 185         set_chunk_tv(frames_per_chunk, afhi->frequency, &afhi->chunk_tv);
 186         ret = 0;
 187 out:
 188         ogg_sync_clear(&oss);
 189         return ret;
 190 }