From 43a105aae3047a4a9b7b3f9bae5fd5ea9c3fc118 Mon Sep 17 00:00:00 2001 From: Thom Johansen Date: Thu, 27 Apr 2006 23:52:55 +0000 Subject: Make libmusepack output the last frame in two passes. Reclaim the IRAM taken in the last commit. Please let me know if you can hear any artifacts or get any broken files from this! git-svn-id: svn://svn.rockbox.org/rockbox/trunk@9825 a1c6a512-1295-4272-9138-f99709370657 --- apps/codecs/libmusepack/decoder.h | 2 +- apps/codecs/libmusepack/mpc_decoder.c | 31 +++++++++++++++++++------------ apps/codecs/libmusepack/musepack.h | 2 +- 3 files changed, 21 insertions(+), 14 deletions(-) diff --git a/apps/codecs/libmusepack/decoder.h b/apps/codecs/libmusepack/decoder.h index 759670ee72..708533b09e 100644 --- a/apps/codecs/libmusepack/decoder.h +++ b/apps/codecs/libmusepack/decoder.h @@ -67,7 +67,7 @@ typedef struct mpc_decoder_t { mpc_uint32_t Zaehler; /// actual index within read-buffer mpc_uint32_t samples_to_skip; - + mpc_uint32_t last_block_samples; mpc_uint32_t FwdJumpInfo; mpc_uint32_t ActDecodePos; diff --git a/apps/codecs/libmusepack/mpc_decoder.c b/apps/codecs/libmusepack/mpc_decoder.c index 1291055327..ee98722a05 100644 --- a/apps/codecs/libmusepack/mpc_decoder.c +++ b/apps/codecs/libmusepack/mpc_decoder.c @@ -351,6 +351,21 @@ mpc_decoder_decode_internal(mpc_decoder *d, MPC_SAMPLE_FORMAT *buffer) mpc_uint32_t FrameBitCnt = 0; + // output the last part of the last frame here, if needed + if (d->last_block_samples > 0) { + output_frame_length = d->last_block_samples; + d->last_block_samples = 0; // it's going to be handled now, so reset it + if (!d->TrueGaplessPresent) { + mpc_decoder_reset_y(d); + } else { + mpc_decoder_bitstream_read(d, 20); + mpc_decoder_read_bitstream_sv7(d); + mpc_decoder_requantisierung(d, d->Max_Band); + } + mpc_decoder_synthese_filter_float(d, buffer); + return output_frame_length; + } + if (d->DecodedFrames >= d->OverallFrames) { return (mpc_uint32_t)(-1); // end of file -> abort decoding } @@ -403,19 +418,10 @@ mpc_decoder_decode_internal(mpc_decoder *d, MPC_SAMPLE_FORMAT *buffer) // additional FilterDecay samples are needed for decay of synthesis filter if (MPC_DECODER_SYNTH_DELAY + mod_block >= MPC_FRAME_LENGTH) { - if (!d->TrueGaplessPresent) { - mpc_decoder_reset_y(d); - } else { - mpc_decoder_bitstream_read(d, 20); - mpc_decoder_read_bitstream_sv7(d); - mpc_decoder_requantisierung(d, d->Max_Band); - } - - mpc_decoder_synthese_filter_float(d, buffer + 2304); - - output_frame_length = MPC_FRAME_LENGTH + FilterDecay; + // this variable will be checked for at the top of the function + d->last_block_samples = FilterDecay; } - else { // there are only FilterDecay samples needed for this frame + else { // there are only FilterDecay samples needed for this frame output_frame_length = FilterDecay; } } @@ -1173,6 +1179,7 @@ void mpc_decoder_setup(mpc_decoder *d, mpc_reader *r) d->OverallFrames = 0; d->DecodedFrames = 0; d->TrueGaplessPresent = 0; + d->last_block_samples = 0; d->WordsRead = 0; d->Max_Band = 0; d->SampleRate = 0; diff --git a/apps/codecs/libmusepack/musepack.h b/apps/codecs/libmusepack/musepack.h index d631c6d05d..9155f3f74d 100644 --- a/apps/codecs/libmusepack/musepack.h +++ b/apps/codecs/libmusepack/musepack.h @@ -58,7 +58,7 @@ extern "C" { enum { MPC_FRAME_LENGTH = (36 * 32), /// samples per mpc frame - MPC_DECODER_BUFFER_LENGTH = 4 * MPC_FRAME_LENGTH /// required buffer size for decoder + MPC_DECODER_BUFFER_LENGTH = 2 * MPC_FRAME_LENGTH /// required buffer size for decoder }; // error codes -- cgit v1.2.3