From b590f3a7bf9103ac7a7a61c48568676201d6824b Mon Sep 17 00:00:00 2001 From: Justin Ruggles Date: Fri, 3 Feb 2012 17:27:31 -0500 Subject: [PATCH] alacenc: only encode frame size in header for a final smaller frame Otherwise it is not needed because it matches the frame size as encoded in the extradata. --- libavcodec/alacenc.c | 13 ++++++++++--- tests/ref/acodec/alac | 4 ++-- 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/libavcodec/alacenc.c b/libavcodec/alacenc.c index 88b2f82..d2a24b1 100644 --- a/libavcodec/alacenc.c +++ b/libavcodec/alacenc.c @@ -120,12 +120,18 @@ static void encode_scalar(AlacEncodeContext *s, int x, static void write_frame_header(AlacEncodeContext *s, int is_verbatim) { + int encode_fs = 0; + + if (s->frame_size < DEFAULT_FRAME_SIZE) + encode_fs = 1; + put_bits(&s->pbctx, 3, s->avctx->channels-1); // No. of channels -1 put_bits(&s->pbctx, 16, 0); // Seems to be zero - put_bits(&s->pbctx, 1, 1); // Sample count is in the header + put_bits(&s->pbctx, 1, encode_fs); // Sample count is in the header put_bits(&s->pbctx, 2, 0); // FIXME: Wasted bytes field put_bits(&s->pbctx, 1, is_verbatim); // Audio block is verbatim - put_bits32(&s->pbctx, s->frame_size); // No. of samples in the frame + if (encode_fs) + put_bits32(&s->pbctx, s->frame_size); // No. of samples in the frame } static void calc_predictor_params(AlacEncodeContext *s, int ch) @@ -380,7 +386,8 @@ static void write_compressed_frame(AlacEncodeContext *s) static av_always_inline int get_max_frame_size(int frame_size, int ch, int bps) { - return FFALIGN(55 + bps * ch * frame_size + 3, 8) / 8; + int header_bits = 23 + 32 * (frame_size < DEFAULT_FRAME_SIZE); + return FFALIGN(header_bits + bps * ch * frame_size + 3, 8) / 8; } static av_cold int alac_encode_close(AVCodecContext *avctx) diff --git a/tests/ref/acodec/alac b/tests/ref/acodec/alac index cef12d0..02752cf 100644 --- a/tests/ref/acodec/alac +++ b/tests/ref/acodec/alac @@ -1,4 +1,4 @@ -db1806d9ffd85c168c2c71a28e6d9229 *./tests/data/acodec/alac.m4a -389410 ./tests/data/acodec/alac.m4a +b9e78aa8b8774a63d187380a47201a37 *./tests/data/acodec/alac.m4a +389154 ./tests/data/acodec/alac.m4a 64151e4bcc2b717aa5a8454d424d6a1f *./tests/data/alac.acodec.out.wav stddev: 0.00 PSNR:999.99 MAXDIFF: 0 bytes: 1058400/ 1058400 -- 2.7.4