src/caf_reader.c

   1 /*
   2  * Copyright (C) 2013 nu774
   3  * For conditions of distribution and use, see copyright notice in COPYING
   4  */
   5 #if HAVE_CONFIG_H
   6 #  include "config.h"
   7 #endif
   8
   9 #if HAVE_STDINT_H
  10 #  include <stdint.h>
  11 #endif
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <stdarg.h>
  17 #include "caf_reader.h"
  18 #include "m4af.h"
  19
  20 typedef struct caf_reader_t {
  21     pcm_reader_vtbl_t *vtbl;
  22     pcm_sample_description_t sample_format;
  23     int64_t length;
  24     int64_t position;
  25     int64_t data_offset;
  26     pcm_io_context_t io;
  27     aacenc_tag_callback_t tag_callback;
  28     void *tag_ctx;
  29     uint8_t chanmap[8];
  30 } caf_reader_t;
  31
  32 static const pcm_sample_description_t *caf_get_format(pcm_reader_t *reader)
  33 {
  34     return &((caf_reader_t *)reader)->sample_format;
  35 }
  36
  37 static int64_t caf_get_length(pcm_reader_t *reader)
  38 {
  39     return ((caf_reader_t *)reader)->length;
  40 }
  41
  42 static int64_t caf_get_position(pcm_reader_t *reader)
  43 {
  44     return ((caf_reader_t *)reader)->position;
  45 }
  46
  47 static void caf_teardown(pcm_reader_t **reader)
  48 {
  49     free(*reader);
  50     *reader = 0;
  51 }
  52
  53 static
  54 uint32_t caf_next_chunk(caf_reader_t *reader, int64_t *chunk_size)
  55 {
  56     uint32_t fcc;
  57     if (pcm_scanb(&reader->io, "LQ", &fcc, chunk_size) == 2)
  58         return fcc;
  59     return 0;
  60 }
  61
  62 static
  63 int caf_desc(caf_reader_t *reader, int64_t chunk_size)
  64 {
  65     double mSampleRate;
  66     uint32_t mFormatID, mFormatFlags, mBytesPerPacket, mFramesPerPacket,
  67              mChannelsPerFrame, mBitsPerChannel;
  68     pcm_sample_description_t *desc = &reader->sample_format;
  69
  70     ENSURE(chunk_size >= 32);
  71     TRY_IO(pcm_scanb(&reader->io, "QLLLLLL", &mSampleRate, &mFormatID,
  72                      &mFormatFlags, &mBytesPerPacket, &mFramesPerPacket,
  73                      &mChannelsPerFrame, &mBitsPerChannel) != 7);
  74
  75     ENSURE(mFormatID == M4AF_FOURCC('l','p','c','m'));
  76     ENSURE(mSampleRate && mBytesPerPacket &&
  77            mChannelsPerFrame >= 1 && mChannelsPerFrame <= 8 &&
  78            mBitsPerChannel && mFramesPerPacket == 1 &&
  79            mBytesPerPacket % mChannelsPerFrame == 0 &&
  80            mBytesPerPacket >= mChannelsPerFrame * ((mBitsPerChannel + 7) / 8));
  81
  82     desc->sample_rate        = mSampleRate;
  83     desc->bits_per_channel   = mBitsPerChannel;
  84     desc->bytes_per_frame    = mBytesPerPacket;
  85     desc->channels_per_frame = mChannelsPerFrame;
  86
  87     switch (mFormatFlags) {
  88     case 0: desc->sample_type = PCM_TYPE_SINT_BE;  break;
  89     case 1: desc->sample_type = PCM_TYPE_FLOAT_BE; break;
  90     case 2: desc->sample_type = PCM_TYPE_SINT;     break;
  91     case 3: desc->sample_type = PCM_TYPE_FLOAT;    break;
  92     default: goto FAIL;
  93     }
  94
  95     TRY_IO(pcm_skip(&reader->io, chunk_size - 32));
  96     return 0;
  97 FAIL:
  98     return -1;
  99 }
 100
 101 static
 102 int caf_info(caf_reader_t *reader, int64_t chunk_size)
 103 {
 104     char *buf, *key, *val, *end;
 105     size_t len;
 106
 107     if (chunk_size < 4 || (buf = malloc(chunk_size)) == 0)
 108         return -1;
 109     pcm_read(&reader->io, buf, chunk_size);
 110     key = buf + 4;
 111     end = buf + chunk_size;
 112     do {
 113         if ((val = key + strlen(key) + 1) < end) {
 114             len = strlen(val);
 115             if (reader->tag_callback)
 116                 reader->tag_callback(reader->tag_ctx, key, val, len);
 117             key = val + len + 1;
 118         }
 119     } while (key < end && val < end);
 120
 121     if (reader->tag_callback)
 122         reader->tag_callback(reader->tag_ctx, 0, 0, 0);
 123     free(buf);
 124     return 0;
 125 }
 126
 127 static
 128 int caf_read_frames(pcm_reader_t *preader, void *buffer, unsigned nframes)
 129 {
 130     int rc;
 131     unsigned i, j, nbytes;
 132     caf_reader_t *reader = (caf_reader_t *)preader;
 133     unsigned bpf = reader->sample_format.bytes_per_frame;
 134     unsigned nchannels = reader->sample_format.channels_per_frame;
 135     unsigned bpc = bpf / nchannels;
 136     uint8_t tmp[64]; /* enough room for maximum bpf: 8ch float64 */
 137     uint8_t *bp;
 138     uint8_t *chanmap = reader->chanmap;
 139
 140     if (nframes > reader->length - reader->position)
 141         nframes = reader->length - reader->position;
 142     nbytes = nframes * bpf;
 143     if (nbytes) {
 144         if ((rc = pcm_read(&reader->io, buffer, nbytes)) < 0)
 145             return -1;
 146         nframes = rc / bpf;
 147         for (bp = buffer, i = 0; i < nframes; ++i, bp += bpf) {
 148             memcpy(tmp, bp, bpf);
 149             for (j = 0; j < nchannels; ++j)
 150                 memcpy(bp + bpc * j, tmp + bpc * chanmap[j], bpc);
 151         }
 152         reader->position += nframes;
 153     }
 154     if (nframes == 0) {
 155         /* fetch info after data chunk */
 156         uint32_t fcc;
 157         int64_t chunk_size;
 158         while ((fcc = caf_next_chunk(reader, &chunk_size)) != 0) {
 159             if (fcc == M4AF_FOURCC('i','n','f','o'))
 160                 TRY_IO(caf_info(reader, chunk_size));
 161             else
 162                 TRY_IO(pcm_skip(&reader->io, chunk_size));
 163         }
 164     }
 165     return nframes;
 166 FAIL:
 167     return 0;
 168 }
 169
 170 static
 171 int caf_parse(caf_reader_t *reader, int64_t *data_length)
 172 {
 173     uint32_t fcc;
 174     int64_t chunk_size;
 175
 176     *data_length = 0;
 177
 178     /* CAFFileHeader */
 179     TRY_IO(pcm_read32be(&reader->io, &fcc));
 180     ENSURE(fcc == M4AF_FOURCC('c','a','f','f'));
 181     TRY_IO(pcm_skip(&reader->io, 4)); /* mFileVersion, mFileFlags */
 182
 183     while ((fcc = caf_next_chunk(reader, &chunk_size)) != 0) {
 184         if (fcc == M4AF_FOURCC('d','e','s','c'))
 185             TRY_IO(caf_desc(reader, chunk_size));
 186         else if (fcc == M4AF_FOURCC('i','n','f','o'))
 187             TRY_IO(caf_info(reader, chunk_size));
 188         else if (fcc == M4AF_FOURCC('c','h','a','n')) {
 189             ENSURE(reader->sample_format.channels_per_frame);
 190             if (apple_chan_chunk(&reader->io, chunk_size,
 191                                  &reader->sample_format, reader->chanmap) < 0)
 192                 goto FAIL;
 193         } else if (fcc == M4AF_FOURCC('d','a','t','a')) {
 194             TRY_IO(pcm_skip(&reader->io, 4)); /* mEditCount */
 195             *data_length = (chunk_size == ~0ULL) ? chunk_size : chunk_size - 4;
 196             reader->data_offset = pcm_tell(&reader->io);
 197             break;
 198         } else
 199             TRY_IO(pcm_skip(&reader->io, chunk_size));
 200     }
 201     ENSURE(reader->sample_format.channels_per_frame);
 202     ENSURE(fcc == M4AF_FOURCC('d','a','t','a'));
 203     return 0;
 204 FAIL:
 205     return -1;
 206 }
 207
 208 static pcm_reader_vtbl_t caf_vtable = {
 209     caf_get_format,
 210     caf_get_length,
 211     caf_get_position,
 212     caf_read_frames,
 213     caf_teardown
 214 };
 215
 216 pcm_reader_t *caf_open(pcm_io_context_t *io,
 217                        aacenc_tag_callback_t tag_callback, void *tag_ctx)
 218 {
 219     caf_reader_t *reader = 0;
 220     int64_t data_length;
 221     unsigned bpf;
 222
 223     if ((reader = calloc(1, sizeof(caf_reader_t))) == 0)
 224         return 0;
 225     memcpy(&reader->io, io, sizeof(pcm_io_context_t));
 226     reader->tag_callback = tag_callback;
 227     reader->tag_ctx = tag_ctx;
 228     memcpy(reader->chanmap, "\000\001\002\003\004\005\006\007", 8);
 229
 230     if (caf_parse(reader, &data_length) < 0) {
 231         free(reader);
 232         return 0;
 233     }
 234     bpf = reader->sample_format.bytes_per_frame;
 235
 236     /* CAF uses -1 to indicate "unknown size" */
 237     if (data_length < 0 || data_length % bpf)
 238         reader->length = INT64_MAX;
 239     else
 240         reader->length = data_length / bpf;
 241
 242     if (reader->length == INT64_MAX) {
 243         if (pcm_seek(&reader->io, 0, SEEK_END) >= 0) {
 244             int64_t size = pcm_tell(&reader->io);
 245             if (size > 0)
 246                 reader->length = (size - reader->data_offset) / bpf;
 247             pcm_seek(&reader->io, reader->data_offset, SEEK_SET);
 248         }
 249     }
 250     reader->vtbl = &caf_vtable;
 251     return (pcm_reader_t *)reader;
 252 }