/* This should be called with a unique decoder instance as the seeking * it does triggers an FAAD bug which results in distorted audio due to * retained state being corrupted. (One suspects NeAACDecPostSeekReset() * should resolve the problem but experimentation suggests not and no * documentation exists describing its use.) */ static int aac_count_time (struct aac_data *data) { NeAACDecFrameInfo frame_info; int samples = 0, bytes = 0, frames = 0; off_t file_size; int16_t *sample_buf; file_size = io_file_size (data->stream); if (file_size == -1) return -1; if (io_seek(data->stream, file_size / 2, SEEK_SET) == -1) return -1; buffer_flush (data); /* Guess track length by decoding the middle 50 frames which have * more than 25% of samples having absolute values greater than 16. */ while (frames < 50) { if (buffer_fill_frame (data) <= 0) break; sample_buf = NeAACDecDecode (data->decoder, &frame_info, buffer_data (data), buffer_length (data)); if (frame_info.error == 0 && frame_info.samples > 0) { unsigned int ix, zeroes = 0; for (ix = 0; ix < frame_info.samples; ix += 1) { if (RANGE(-16, sample_buf[ix], 16)) zeroes += 1; } if (zeroes * 4 < frame_info.samples) { samples += frame_info.samples; bytes += frame_info.bytesconsumed; frames += 1; } } if (frame_info.bytesconsumed == 0) break; buffer_consume (data, frame_info.bytesconsumed); } if (frames == 0) return -1; samples /= frames; samples /= data->channels; bytes /= frames; return ((file_size / bytes) * samples) / data->sample_rate; }
static int aac_count_time (struct aac_data *data) { NeAACDecFrameInfo frame_info; int samples = 0, bytes = 0, frames = 0; off_t file_size; char *sample_buf; long saved_pos; file_size = io_file_size (data->stream); if (file_size == -1) return -1; saved_pos = io_tell (data->stream); /* guess track length by decoding the first 10 frames */ while (frames < 10) { if (buffer_fill_frame(data) <= 0) break; sample_buf = NeAACDecDecode(data->decoder, &frame_info, buffer_data(data), buffer_length(data)); if (frame_info.error == 0 && frame_info.samples > 0) { samples += frame_info.samples; bytes += frame_info.bytesconsumed; frames++; } if (frame_info.bytesconsumed == 0) break; buffer_consume (data, frame_info.bytesconsumed); } if (io_seek(data->stream, saved_pos, SEEK_SET) == (off_t)-1) { logit ("Can't seek after couting time"); return -1; } if (frames == 0) return -1; samples /= frames; samples /= data->channels; bytes /= frames; return ((file_size / bytes) * samples) / data->sample_rate; }
static void *aac_open_internal (struct io_stream *stream, const char *fname) { struct aac_data *data; NeAACDecConfigurationPtr neaac_cfg; unsigned char channels; unsigned long sample_rate; int n; /* init private struct */ data = xcalloc (1, sizeof *data); data->decoder = NeAACDecOpen(); /* set decoder config */ neaac_cfg = NeAACDecGetCurrentConfiguration(data->decoder); neaac_cfg->outputFormat = FAAD_FMT_16BIT; /* force 16 bit audio */ neaac_cfg->downMatrix = 1; /* 5.1 -> stereo */ neaac_cfg->dontUpSampleImplicitSBR = 0; /* upsample, please! */ NeAACDecSetConfiguration(data->decoder, neaac_cfg); if (stream) data->stream = stream; else { data->stream = io_open (fname, 1); if (!io_ok(data->stream)) { decoder_error (&data->error, ERROR_FATAL, 0, "Can't open AAC file: %s", io_strerror(data->stream)); return data; } } /* find a frame */ if (buffer_fill_frame(data) <= 0) { decoder_error (&data->error, ERROR_FATAL, 0, "Not a valid (or unsupported) AAC file"); return data; } /* in case of a bug, make sure there is at least some data * in the buffer for NeAACDecInit() to work with. */ if (buffer_fill_min(data, 256) <= 0) { decoder_error (&data->error, ERROR_FATAL, 0, "AAC file/stream too short"); return data; } /* init decoder, returns the length of the header (if any) */ channels = (unsigned char)data->channels; sample_rate = data->sample_rate; n = NeAACDecInit (data->decoder, buffer_data(data), buffer_length(data), &sample_rate, &channels); data->channels = channels; data->sample_rate = (int)sample_rate; if (n < 0) { decoder_error (&data->error, ERROR_FATAL, 0, "libfaad can't open this stream"); return data; } logit ("sample rate %dHz, channels %d", data->sample_rate, data->channels); if (!data->sample_rate || !data->channels) { decoder_error (&data->error, ERROR_FATAL, 0, "Invalid AAC sound parameters"); return data; } /* skip the header */ logit ("skipping header (%d bytes)", n); buffer_consume (data, n); /*NeAACDecInitDRM(data->decoder, data->sample_rate, data->channels);*/ data->ok = 1; return data; }