diff --git a/libavcodec/alacenc.c b/libavcodec/alacenc.c index 9095611289..804cc7b17b 100644 --- a/libavcodec/alacenc.c +++ b/libavcodec/alacenc.c @@ -38,6 +38,7 @@ #define DEFAULT_MAX_PRED_ORDER 6 #define DEFAULT_MIN_PRED_ORDER 4 #define ALAC_MAX_LPC_PRECISION 9 +#define ALAC_MIN_LPC_SHIFT 0 #define ALAC_MAX_LPC_SHIFT 9 #define ALAC_CHMODE_LEFT_RIGHT 0 @@ -171,7 +172,8 @@ static void calc_predictor_params(AlacEncodeContext *s, int ch) s->max_prediction_order, ALAC_MAX_LPC_PRECISION, coefs, shift, FF_LPC_TYPE_LEVINSON, 0, - ORDER_METHOD_EST, ALAC_MAX_LPC_SHIFT, 1); + ORDER_METHOD_EST, ALAC_MIN_LPC_SHIFT, + ALAC_MAX_LPC_SHIFT, 1); s->lpc[ch].lpc_order = opt_order; s->lpc[ch].lpc_quant = shift[opt_order-1]; diff --git a/libavcodec/flacenc.c b/libavcodec/flacenc.c index 9d6a742938..3575f5391d 100644 --- a/libavcodec/flacenc.c +++ b/libavcodec/flacenc.c @@ -44,6 +44,7 @@ #define MAX_PARTITION_ORDER 8 #define MAX_PARTITIONS (1 << MAX_PARTITION_ORDER) #define MAX_LPC_PRECISION 15 +#define MIN_LPC_SHIFT 0 #define MAX_LPC_SHIFT 15 enum CodingMode { @@ -884,7 +885,7 @@ static int encode_residual_ch(FlacEncodeContext *s, int ch) opt_order = ff_lpc_calc_coefs(&s->lpc_ctx, smp, n, min_order, max_order, s->options.lpc_coeff_precision, coefs, shift, s->options.lpc_type, s->options.lpc_passes, omethod, - MAX_LPC_SHIFT, 0); + MIN_LPC_SHIFT, MAX_LPC_SHIFT, 0); if (omethod == ORDER_METHOD_2LEVEL || omethod == ORDER_METHOD_4LEVEL || diff --git a/libavcodec/lpc.c b/libavcodec/lpc.c index 052aeaa191..f8da1e1266 100644 --- a/libavcodec/lpc.c +++ b/libavcodec/lpc.c @@ -93,7 +93,8 @@ static void lpc_compute_autocorr_c(const double *data, int len, int lag, * Quantize LPC coefficients */ static void quantize_lpc_coefs(double *lpc_in, int order, int precision, - int32_t *lpc_out, int *shift, int max_shift, int zero_shift) + int32_t *lpc_out, int *shift, int min_shift, + int max_shift, int zero_shift) { int i; double cmax, error; @@ -118,7 +119,7 @@ static void quantize_lpc_coefs(double *lpc_in, int order, int precision, /* calculate level shift which scales max coeff to available bits */ sh = max_shift; - while((cmax * (1 << sh) > qmax) && (sh > 0)) { + while((cmax * (1 << sh) > qmax) && (sh > min_shift)) { sh--; } @@ -201,7 +202,7 @@ int ff_lpc_calc_coefs(LPCContext *s, int max_order, int precision, int32_t coefs[][MAX_LPC_ORDER], int *shift, enum FFLPCType lpc_type, int lpc_passes, - int omethod, int max_shift, int zero_shift) + int omethod, int min_shift, int max_shift, int zero_shift) { double autoc[MAX_LPC_ORDER+1]; double ref[MAX_LPC_ORDER] = { 0 }; @@ -284,10 +285,12 @@ int ff_lpc_calc_coefs(LPCContext *s, if(omethod == ORDER_METHOD_EST) { opt_order = estimate_best_order(ref, min_order, max_order); i = opt_order-1; - quantize_lpc_coefs(lpc[i], i+1, precision, coefs[i], &shift[i], max_shift, zero_shift); + quantize_lpc_coefs(lpc[i], i+1, precision, coefs[i], &shift[i], + min_shift, max_shift, zero_shift); } else { for(i=min_order-1; ilpc_ctx, lpc_data, NBLOCKS * BLOCKSIZE, LPC_ORDER, LPC_ORDER, 16, lpc_coefs, shift, FF_LPC_TYPE_LEVINSON, - 0, ORDER_METHOD_EST, 12, 0); + 0, ORDER_METHOD_EST, 0, 12, 0); for (i = 0; i < LPC_ORDER; i++) block_coefs[NBLOCKS - 1][i] = -(lpc_coefs[LPC_ORDER - 1][i] << (12 - shift[LPC_ORDER - 1]));