The reference encoder does not generate any streams using this, but the
reference decoder can handle it, so we should as well.
---
Reimplemented the patch slightly differently to avoid code duplication
to to check for unknown prediction types.
libavcodec/alac.c | 37 +++++++++++++++++++++----------------
1 files changed, 21 insertions(+), 16 deletions(-)
diff --git a/libavcodec/alac.c b/libavcodec/alac.c
index eb6c1cf..278cc99 100644
--- a/libavcodec/alac.c
+++ b/libavcodec/alac.c
@@ -452,24 +452,29 @@ static int alac_decode_frame(AVCodecContext *avctx, void
*data,
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 */
--
1.7.1
_______________________________________________
libav-devel mailing list
[email protected]
https://lists.libav.org/mailman/listinfo/libav-devel
