ricemodifier[ch] * alac->setinfo_rice_historymult / 4,
(1 << alac->setinfo_rice_kmodifier) - 1);
- if (prediction_type[ch] == 0) {
- /* adaptive fir */
- predictor_decompress_fir_adapt(alac->predicterror_buffer[ch],
- alac->outputsamples_buffer[ch],
- outputsamples,
- readsamplesize,
- predictor_coef_table[ch],
- predictor_coef_num[ch],
- prediction_quantitization[ch]);
- } else {
- av_log(avctx, AV_LOG_ERROR, "FIXME: unhandled prediction type: %i\n", prediction_type[ch]);
- /* I think the only other prediction type (or perhaps this is
- * just a boolean?) runs adaptive fir twice.. like:
- * predictor_decompress_fir_adapt(predictor_error, tempout, ...)
- * predictor_decompress_fir_adapt(predictor_error, outputsamples ...)
- * little strange..
+ /* adaptive FIR filter */
+ if (prediction_type[ch] == 15) {
+ /* Prediction type 15 runs the adaptive FIR twice.
+ * The first pass uses the special-case coef_num = 31, while
+ * the second pass uses the coefs from the bitstream.
+ *
+ * However, this prediction type is not currently used by the
+ * reference encoder.
*/
+ predictor_decompress_fir_adapt(alac->predicterror_buffer[ch],
+ alac->predicterror_buffer[ch],
+ outputsamples, readsamplesize,
+ NULL, 31, 0);
+ } else if (prediction_type[ch] > 0) {
+ av_log(avctx, AV_LOG_WARNING, "unknown prediction type: %i\n",
+ prediction_type[ch]);
}
+ predictor_decompress_fir_adapt(alac->predicterror_buffer[ch],
+ alac->outputsamples_buffer[ch],
+ outputsamples, readsamplesize,
+ predictor_coef_table[ch],
+ predictor_coef_num[ch],
+ prediction_quantitization[ch]);
}
} else {
/* not compressed, easy case */
static int alac_set_info(ALACContext *alac)
{
- const unsigned char *ptr = alac->avctx->extradata;
+ GetByteContext gb;
- ptr += 4; /* size */
- ptr += 4; /* alac */
- ptr += 4; /* version */
+ bytestream2_init(&gb, alac->avctx->extradata,
+ alac->avctx->extradata_size);
- if(AV_RB32(ptr) >= UINT_MAX/4){
- av_log(alac->avctx, AV_LOG_ERROR, "setinfo_max_samples_per_frame too large\n");
- return -1;
- }
+ bytestream2_skipu(&gb, 12); // size:4, alac:4, version:4
/* buffer size / 2 ? */
- alac->setinfo_max_samples_per_frame = bytestream_get_be32(&ptr);
- ptr++; /* compatible version */
- alac->setinfo_sample_size = *ptr++;
- alac->setinfo_rice_historymult = *ptr++;
- alac->setinfo_rice_initialhistory = *ptr++;
- alac->setinfo_rice_kmodifier = *ptr++;
- alac->numchannels = *ptr++;
- bytestream_get_be16(&ptr); /* maxRun */
- bytestream_get_be32(&ptr); /* max coded frame size */
- bytestream_get_be32(&ptr); /* average bitrate */
- bytestream_get_be32(&ptr); /* samplerate */
+ alac->setinfo_max_samples_per_frame = bytestream2_get_be32u(&gb);
+ if (alac->setinfo_max_samples_per_frame >= UINT_MAX/4){
+ av_log(alac->avctx, AV_LOG_ERROR,
+ "setinfo_max_samples_per_frame too large\n");
+ return AVERROR_INVALIDDATA;
+ }
+ bytestream2_skipu(&gb, 1); // compatible version
+ alac->setinfo_sample_size = bytestream2_get_byteu(&gb);
+ alac->setinfo_rice_historymult = bytestream2_get_byteu(&gb);
+ alac->setinfo_rice_initialhistory = bytestream2_get_byteu(&gb);
+ alac->setinfo_rice_kmodifier = bytestream2_get_byteu(&gb);
+ alac->numchannels = bytestream2_get_byteu(&gb);
+ bytestream2_get_be16u(&gb); // maxRun
+ bytestream2_get_be32u(&gb); // max coded frame size
+ bytestream2_get_be32u(&gb); // average bitrate
+ bytestream2_get_be32u(&gb); // samplerate
return 0;
}
.close = alac_decode_close,
.decode = alac_decode_frame,
.capabilities = CODEC_CAP_DR1,
- .long_name = NULL_IF_CONFIG_SMALL("ALAC (Apple Lossless Audio Codec)"),
+ .long_name = NULL_IF_CONFIG_SMALL("ALAC (Apple Lossless Audio Codec)"),
};