The actual predictor value, set by the trellis code, never was written back into the variable that was written into the block header. This was accidentally removed in b304244b.
This significantly improves the audio quality of the trellis case, which was plain broken since b304244b. Encoding IMA QT with trellis still actually gives a slightly worse quality than without trellis, since the trellis encoder doesn't use the exact same way of rounding as in adpcm_ima_qt_compress_sample and adpcm_ima_qt_expand_nibble. CC: [email protected] --- libavcodec/adpcmenc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/libavcodec/adpcmenc.c b/libavcodec/adpcmenc.c index 2cf8d6f..341dda4 100644 --- a/libavcodec/adpcmenc.c +++ b/libavcodec/adpcmenc.c @@ -553,6 +553,7 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, 64, 1); for (i = 0; i < 64; i++) put_bits(&pb, 4, buf[i ^ 1]); + status->prev_sample = status->predictor; } else { for (i = 0; i < 64; i += 2) { int t1, t2; -- 1.8.5.2 (Apple Git-48) _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
