int quicktime_read_chunk(quicktime_t *file, char *output, int track, long chunk, long byte_start, long byte_len)
{
quicktime_set_position(file, quicktime_chunk_to_offset(file->atracks[track].track, chunk) + byte_start);
if(quicktime_read_data(file, output, byte_len)) return 0;
else
return 1;
}
long quicktime_sample_to_offset(quicktime_trak_t *trak, long sample)
{
long chunk, chunk_sample, chunk_offset1, chunk_offset2;
if (trak == NULL) {
return -1;
}
quicktime_chunk_of_sample(&chunk_sample, &chunk, trak, sample);
chunk_offset1 = quicktime_chunk_to_offset(trak, chunk);
chunk_offset2 = chunk_offset1 + quicktime_sample_range_size(trak, chunk_sample, sample);
/*printf("quicktime_sample_to_offset chunk %d sample %d chunk_offset %d chunk_sample %d chunk_offset + samples %d\n", */
/* chunk, sample, chunk_offset1, chunk_sample, chunk_offset2); */
return chunk_offset2;
}
static int decode(quicktime_t *file,
int16_t *output_i,
float *output_f,
long samples,
int track,
int channel)
{
quicktime_audio_map_t *track_map = &(file->atracks[track]);
quicktime_trak_t *trak = track_map->track;
quicktime_qdm2_codec_t *codec = ((quicktime_codec_t*)track_map->codec)->priv;
quicktime_stsd_table_t *stsd_table = &trak->mdia.minf.stbl.stsd.table[0];
int64_t current_position = track_map->current_position;
int64_t end_position = current_position + samples;
quicktime_frma_t *frma = &stsd_table->frma;
int channels = track_map->channels;
int i, j;
int debug = 0;
int64_t chunk_sample;
// Initialize decoder
if(!codec->decoder_initialized)
{
pthread_mutex_lock(&ffmpeg_lock);
if(!ffmpeg_initialized)
{
ffmpeg_initialized = 1;
av_register_all();
}
codec->decoder = avcodec_find_decoder(CODEC_ID_QDM2);
if(!codec->decoder)
{
printf("qdm2.c: decode: no ffmpeg decoder found.\n");
return 1;
}
// allocate the codec and fill in header
AVCodecContext *context = avcodec_alloc_context3(codec->decoder);
codec->decoder_context = context;
codec->decoder_context->sample_rate = trak->mdia.minf.stbl.stsd.table[0].sample_rate;
codec->decoder_context->channels = track_map->channels;
if(frma->data && frma->data_size)
{
context->extradata = (unsigned char *)frma->data;
context->extradata_size = frma->data_size;
}
if(file->cpus > 1)
{
// avcodec_thread_init(context, file->cpus);
context->thread_count = file->cpus;
}
if(avcodec_open2(context, codec->decoder, 0) < 0)
{
printf("qdm2.c: decode: avcodec_open failed.\n");
return 1;
}
pthread_mutex_unlock(&ffmpeg_lock);
codec->input_buffer = calloc(sizeof(int16_t),
track_map->channels * OUTPUT_ALLOCATION);
codec->input_allocated = OUTPUT_ALLOCATION;
codec->decoder_initialized = 1;
}
if(samples > OUTPUT_ALLOCATION)
{
printf("qdm2: decode: can't decode more than 0x%x samples at a time.\n",
OUTPUT_ALLOCATION);
return 1;
}
if(debug)
{
printf("qdm2 decode: current_position=%jd end_position=%jd input_size=%d input_end=%jd\n",
current_position, end_position, codec->input_size, codec->input_end);
}
// printf("qdm2 decode: current_position=%lld end_position=%lld chunk_sample=%lld chunk=%lld\n",
// current_position,
// end_position,
// chunk_sample,
// chunk);
if(current_position < codec->input_end - codec->input_size ||
current_position > codec->input_end)
{
// Desired start point is outside existing range. Reposition buffer pointer
// to start time of nearest chunk and start over.
quicktime_chunk_of_sample(&chunk_sample,
&codec->current_chunk,
trak,
current_position);
codec->input_size = 0;
codec->input_ptr = 0;
codec->input_end = chunk_sample;
}
// Decode complete chunks until samples is reached
int total_chunks = trak->mdia.minf.stbl.stco.total_entries;
while(codec->input_end < end_position)
{
int64_t offset = quicktime_chunk_to_offset(file,
trak,
codec->current_chunk);
int64_t max_offset = quicktime_chunk_to_offset(file,
trak,
codec->current_chunk + 1);
quicktime_set_position(file, offset);
allocate_compressed(codec, 3);
if(debug)
{
printf("qdm2 decode: input_end=%jd chunk=%jd offset=0x%jx\n",
codec->input_end, codec->current_chunk, offset);
}
// Read fragments of chunk
while(1)
{
// Hit next chunk of audio
if(max_offset > offset && quicktime_position(file) >= max_offset) break;
if(!quicktime_read_data(file,
(char*)codec->compressed_buffer + codec->compressed_size,
3))
break;
if(codec->compressed_buffer[codec->compressed_size] != 0x82)
{
// printf("qdm2: decode: position=0x%llx\n", quicktime_position(file));
break;
}
int fragment_size = 3 + ((codec->compressed_buffer[codec->compressed_size + 1] << 8) |
codec->compressed_buffer[codec->compressed_size + 2]);
// Sanity check
if(fragment_size > OUTPUT_ALLOCATION) break;
// Expand compressed buffer
allocate_compressed(codec,
codec->compressed_size + fragment_size + 1024);
if(!quicktime_read_data(file,
(char*)codec->compressed_buffer + codec->compressed_size + 3,
fragment_size - 3))
break;
codec->compressed_size += fragment_size;
AVPacket avpkt;
av_init_packet(&avpkt);
avpkt.data = codec->compressed_buffer;
avpkt.size = codec->compressed_size;
int count = 0;
// Repeat this sequence until ffmpeg stops outputting samples
while(1)
{
if(!codec->temp_buffer)
codec->temp_buffer = calloc(sizeof(int16_t), OUTPUT_ALLOCATION);
int bytes_decoded = OUTPUT_ALLOCATION * sizeof(int16_t);
int result = quicktime_decode_audio3(codec->decoder_context,
codec->temp_buffer, &bytes_decoded, &avpkt);
// Shift compressed buffer
if(result > 0)
{
avpkt.size -= result;
avpkt.data += result;
count += result;
}
//printf("avcodec_decode_audio result=%d bytes_decoded=%d fragment_size=%d codec->compressed_size=%d\n",
//result, bytes_decoded, fragment_size, codec->compressed_size);
/*
* static FILE *test = 0;
* if(!test) test = fopen("/tmp/debug", "w");
* fwrite(codec->temp_buffer, 1, bytes_decoded, test);
* fflush(test);
*/
for(i = 0; i < bytes_decoded / channels / sizeof(int16_t); i++)
{
for(j = 0; j < channels; j++)
codec->input_buffer[codec->input_ptr * channels + j] =
codec->temp_buffer[i * channels + j];
codec->input_ptr++;
if(codec->input_ptr >= codec->input_allocated)
codec->input_ptr = 0;
}
codec->input_end += bytes_decoded / channels / sizeof(int16_t);
codec->input_size += bytes_decoded / channels / sizeof(int16_t);
if(bytes_decoded <= 0) break;
}
if( count > 0 ) {
memcpy(codec->compressed_buffer,
codec->compressed_buffer + count,
codec->compressed_size -= count);
}
}
codec->current_chunk++;
if(codec->current_chunk >= total_chunks) break;
}
// Transfer from buffer to output
int input_ptr = codec->input_ptr - (codec->input_end - current_position);
if(input_ptr < 0) input_ptr += codec->input_allocated;
if(output_i)
{
for(i = 0; i < samples; i++)
{
output_i[i] = codec->input_buffer[input_ptr * channels + channel];
input_ptr++;
if(input_ptr >= codec->input_allocated) input_ptr = 0;
}
}
else
if(output_f)
{
for(i = 0; i < samples; i++)
{
output_f[i] = (float)codec->input_buffer[input_ptr * channels + channel] / 32768.0;
input_ptr++;
if(input_ptr >= codec->input_allocated) input_ptr = 0;
}
}
return 0;
}