This is an automated email from the git hooks/post-receive script. It was generated because a ref change was pushed to the repository containing the project "AMR-WB decoder". The branch, master has been updated via c2a8e2ad2d9c51c9d1f7b9101175db05f2fecabb (commit) from 958f5f8c6f85ce8db4f9b583070804d9a019bd46 (commit) Those revisions listed above that are new to this repository have not appeared on any other notification email; so we list those revisions in full, below. - Log ----------------------------------------------------------------- commit c2a8e2ad2d9c51c9d1f7b9101175db05f2fecabb Author: Marcelo Povoa <marspeoplester@gmail.com> Date: Wed Jul 21 01:46:19 2010 -0300 Generate the gain-scaled high band excitation (6.3.1) diff --git a/libavcodec/amrwbdec.c b/libavcodec/amrwbdec.c index 2fcc61a..063afc0 100644 --- a/libavcodec/amrwbdec.c +++ b/libavcodec/amrwbdec.c @@ -19,6 +19,8 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ +#include "libavutil/lfg.h" + #include "avcodec.h" #include "get_bits.h" #include "lsp.h" @@ -73,6 +75,8 @@ typedef struct { float demph_mem[1]; ///< previous value in the de-emphasis filter float hpf_mem[4]; ///< previous values in the high-pass filter + + AVLFG prng; ///< random number generator for white noise excitation } AMRWBContext; static av_cold int amrwb_decode_init(AVCodecContext *avctx) @@ -82,6 +86,8 @@ static av_cold int amrwb_decode_init(AVCodecContext *avctx) avctx->sample_fmt = SAMPLE_FMT_FLT; + av_lfg_init(&ctx->prng, 1); + ctx->excitation = &ctx->excitation_buf[PITCH_MAX + LP_ORDER + 1]; for (i = 0; i < LP_ORDER; i++) { @@ -876,17 +882,17 @@ static void pitch_enhancer(float *fixed_vector, float voice_fac) * * @param ctx [in] pointer to the AMRWBContext * @param lpc [in] pointer to the LPC coefficients + * @param excitation [out] buffer for synthesis final excitation * @param fixed_gain [in] fixed codebook gain for synthesis * @param fixed_vector [in] algebraic codebook vector * @param samples [out] pointer to the output speech samples * @param overflow [in] 16-bit predicted overflow flag */ -static uint8_t synthesis(AMRWBContext *ctx, float *lpc, +static uint8_t synthesis(AMRWBContext *ctx, float *lpc, float *excitation, float fixed_gain, const float *fixed_vector, float *samples, uint8_t overflow) { int i; - float excitation[AMRWB_SUBFRAME_SIZE]; // if an overflow has been detected, the pitch vector is scaled down by a // factor of 4 @@ -998,11 +1004,39 @@ static float find_hb_gain(AMRWBContext *ctx, const float *synth, tilt = ff_dot_productf(synth, synth + 1, AMRWB_SUBFRAME_SIZE - 1) / ff_dot_productf(synth, synth, AMRWB_SUBFRAME_SIZE); + tilt = FFMAX(0.0, tilt); + /* return gain bounded by [0.1, 1.0] */ return FFMAX(0.1, FFMIN(1.0, (1.0 - tilt) * (1.25 - 0.25 * wsp))); } /** + * Generate the high band excitation with the same energy from the lower + * one and scaled by the given gain + * + * @param ctx [in] the context + * @param hb_exc [out] buffer for the excitation + * @param synth_exc [in] excitation used for synthesis + * @param hb_gain [in] wanted excitation gain + */ +static void scaled_hb_excitation(AMRWBContext *ctx, float *hb_exc, + const float *synth_exc, float hb_gain) +{ + int i; + float energy = ff_dot_productf(synth_exc, synth_exc, AMRWB_SUBFRAME_SIZE); + + /* Generate a white-noise excitation */ + for (i = 0; i < AMRWB_SUBFRAME_SIZE; i++) + hb_exc[i] = 32768.0 - (uint16_t) av_lfg_get(&ctx->prng) / 65536.0; + + ff_scale_vector_to_given_sum_of_squares(hb_exc, hb_exc, energy, + AMRWB_SUBFRAME_SIZE); + + for (i = 0; i < AMRWB_SUBFRAME_SIZE; i++) + hb_exc[i] *= hb_gain; +} + +/** * Update context state before the next subframe */ static void update_sub_state(AMRWBContext *ctx) @@ -1024,6 +1058,8 @@ static int amrwb_decode_frame(AVCodecContext *avctx, void *data, int *data_size, float *synth_fixed_vector; // pointer to the fixed vector that synthesis should use float synth_fixed_gain; // the fixed gain that synthesis should use float voice_fac, stab_fac; // parameters used for gain smoothing + float synth_exc[AMRWB_SUBFRAME_SIZE]; // post-processed excitation for synthesis + float hb_exc[AMRWB_SUBFRAME_SIZE]; // excitation for the high frequency band float hb_gain; int sub, i; @@ -1102,12 +1138,12 @@ static int amrwb_decode_frame(AVCodecContext *avctx, void *data, int *data_size, pitch_enhancer(synth_fixed_vector, voice_fac); - if (synthesis(ctx, ctx->lp_coef[sub], synth_fixed_gain, + if (synthesis(ctx, ctx->lp_coef[sub], synth_exc, synth_fixed_gain, synth_fixed_vector, &ctx->samples_in[LP_ORDER], 0)) // overflow detected -> rerun synthesis scaling pitch vector down // by a factor of 4, skipping pitch vector contribution emphasis // and adaptive gain control - synthesis(ctx, ctx->lp_coef[sub], synth_fixed_gain, + synthesis(ctx, ctx->lp_coef[sub], synth_exc, synth_fixed_gain, synth_fixed_vector, &ctx->samples_in[LP_ORDER], 1); /* Synthesis speech post-processing */ @@ -1126,6 +1162,8 @@ static int amrwb_decode_frame(AVCodecContext *avctx, void *data, int *data_size, hb_gain = find_hb_gain(ctx, &ctx->samples_in[LP_ORDER], cur_subframe->hb_gain, cf->vad); + scaled_hb_excitation(ctx, hb_exc, synth_exc, hb_gain); + /* Update buffers and history */ ff_clear_fixed_vector(ctx->fixed_vector, &fixed_sparse, AMRWB_SUBFRAME_SIZE); ----------------------------------------------------------------------- Summary of changes: libavcodec/amrwbdec.c | 46 ++++++++++++++++++++++++++++++++++++++++++---- 1 files changed, 42 insertions(+), 4 deletions(-) hooks/post-receive -- AMR-WB decoder