yading@10: /* yading@10: * RealAudio 2.0 (28.8K) yading@10: * Copyright (c) 2003 the ffmpeg project yading@10: * yading@10: * This file is part of FFmpeg. yading@10: * yading@10: * FFmpeg is free software; you can redistribute it and/or yading@10: * modify it under the terms of the GNU Lesser General Public yading@10: * License as published by the Free Software Foundation; either yading@10: * version 2.1 of the License, or (at your option) any later version. yading@10: * yading@10: * FFmpeg is distributed in the hope that it will be useful, yading@10: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@10: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@10: * Lesser General Public License for more details. yading@10: * yading@10: * You should have received a copy of the GNU Lesser General Public yading@10: * License along with FFmpeg; if not, write to the Free Software yading@10: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@10: */ yading@10: yading@10: #include "libavutil/channel_layout.h" yading@10: #include "libavutil/float_dsp.h" yading@10: #include "libavutil/internal.h" yading@10: #include "avcodec.h" yading@10: #include "internal.h" yading@10: #define BITSTREAM_READER_LE yading@10: #include "get_bits.h" yading@10: #include "ra288.h" yading@10: #include "lpc.h" yading@10: #include "celp_filters.h" yading@10: yading@10: #define MAX_BACKWARD_FILTER_ORDER 36 yading@10: #define MAX_BACKWARD_FILTER_LEN 40 yading@10: #define MAX_BACKWARD_FILTER_NONREC 35 yading@10: yading@10: #define RA288_BLOCK_SIZE 5 yading@10: #define RA288_BLOCKS_PER_FRAME 32 yading@10: yading@10: typedef struct { yading@10: AVFloatDSPContext fdsp; yading@10: DECLARE_ALIGNED(32, float, sp_lpc)[FFALIGN(36, 16)]; ///< LPC coefficients for speech data (spec: A) yading@10: DECLARE_ALIGNED(32, float, gain_lpc)[FFALIGN(10, 16)]; ///< LPC coefficients for gain (spec: GB) yading@10: yading@10: /** speech data history (spec: SB). yading@10: * Its first 70 coefficients are updated only at backward filtering. yading@10: */ yading@10: float sp_hist[111]; yading@10: yading@10: /// speech part of the gain autocorrelation (spec: REXP) yading@10: float sp_rec[37]; yading@10: yading@10: /** log-gain history (spec: SBLG). yading@10: * Its first 28 coefficients are updated only at backward filtering. yading@10: */ yading@10: float gain_hist[38]; yading@10: yading@10: /// recursive part of the gain autocorrelation (spec: REXPLG) yading@10: float gain_rec[11]; yading@10: } RA288Context; yading@10: yading@10: static av_cold int ra288_decode_init(AVCodecContext *avctx) yading@10: { yading@10: RA288Context *ractx = avctx->priv_data; yading@10: yading@10: avctx->channels = 1; yading@10: avctx->channel_layout = AV_CH_LAYOUT_MONO; yading@10: avctx->sample_fmt = AV_SAMPLE_FMT_FLT; yading@10: yading@10: if (avctx->block_align <= 0) { yading@10: av_log(avctx, AV_LOG_ERROR, "unsupported block align\n"); yading@10: return AVERROR_PATCHWELCOME; yading@10: } yading@10: yading@10: avpriv_float_dsp_init(&ractx->fdsp, avctx->flags & CODEC_FLAG_BITEXACT); yading@10: yading@10: return 0; yading@10: } yading@10: yading@10: static void convolve(float *tgt, const float *src, int len, int n) yading@10: { yading@10: for (; n >= 0; n--) yading@10: tgt[n] = avpriv_scalarproduct_float_c(src, src - n, len); yading@10: yading@10: } yading@10: yading@10: static void decode(RA288Context *ractx, float gain, int cb_coef) yading@10: { yading@10: int i; yading@10: double sumsum; yading@10: float sum, buffer[5]; yading@10: float *block = ractx->sp_hist + 70 + 36; // current block yading@10: float *gain_block = ractx->gain_hist + 28; yading@10: yading@10: memmove(ractx->sp_hist + 70, ractx->sp_hist + 75, 36*sizeof(*block)); yading@10: yading@10: /* block 46 of G.728 spec */ yading@10: sum = 32.; yading@10: for (i=0; i < 10; i++) yading@10: sum -= gain_block[9-i] * ractx->gain_lpc[i]; yading@10: yading@10: /* block 47 of G.728 spec */ yading@10: sum = av_clipf(sum, 0, 60); yading@10: yading@10: /* block 48 of G.728 spec */ yading@10: /* exp(sum * 0.1151292546497) == pow(10.0,sum/20) */ yading@10: sumsum = exp(sum * 0.1151292546497) * gain * (1.0/(1<<23)); yading@10: yading@10: for (i=0; i < 5; i++) yading@10: buffer[i] = codetable[cb_coef][i] * sumsum; yading@10: yading@10: sum = avpriv_scalarproduct_float_c(buffer, buffer, 5); yading@10: yading@10: sum = FFMAX(sum, 5. / (1<<24)); yading@10: yading@10: /* shift and store */ yading@10: memmove(gain_block, gain_block + 1, 9 * sizeof(*gain_block)); yading@10: yading@10: gain_block[9] = 10 * log10(sum) + (10*log10(((1<<24)/5.)) - 32); yading@10: yading@10: ff_celp_lp_synthesis_filterf(block, ractx->sp_lpc, buffer, 5, 36); yading@10: } yading@10: yading@10: /** yading@10: * Hybrid window filtering, see blocks 36 and 49 of the G.728 specification. yading@10: * yading@10: * @param order filter order yading@10: * @param n input length yading@10: * @param non_rec number of non-recursive samples yading@10: * @param out filter output yading@10: * @param hist pointer to the input history of the filter yading@10: * @param out pointer to the non-recursive part of the output yading@10: * @param out2 pointer to the recursive part of the output yading@10: * @param window pointer to the windowing function table yading@10: */ yading@10: static void do_hybrid_window(RA288Context *ractx, yading@10: int order, int n, int non_rec, float *out, yading@10: float *hist, float *out2, const float *window) yading@10: { yading@10: int i; yading@10: float buffer1[MAX_BACKWARD_FILTER_ORDER + 1]; yading@10: float buffer2[MAX_BACKWARD_FILTER_ORDER + 1]; yading@10: LOCAL_ALIGNED(32, float, work, [FFALIGN(MAX_BACKWARD_FILTER_ORDER + yading@10: MAX_BACKWARD_FILTER_LEN + yading@10: MAX_BACKWARD_FILTER_NONREC, 16)]); yading@10: yading@10: av_assert2(order>=0); yading@10: yading@10: ractx->fdsp.vector_fmul(work, window, hist, FFALIGN(order + n + non_rec, 16)); yading@10: yading@10: convolve(buffer1, work + order , n , order); yading@10: convolve(buffer2, work + order + n, non_rec, order); yading@10: yading@10: for (i=0; i <= order; i++) { yading@10: out2[i] = out2[i] * 0.5625 + buffer1[i]; yading@10: out [i] = out2[i] + buffer2[i]; yading@10: } yading@10: yading@10: /* Multiply by the white noise correcting factor (WNCF). */ yading@10: *out *= 257./256.; yading@10: } yading@10: yading@10: /** yading@10: * Backward synthesis filter, find the LPC coefficients from past speech data. yading@10: */ yading@10: static void backward_filter(RA288Context *ractx, yading@10: float *hist, float *rec, const float *window, yading@10: float *lpc, const float *tab, yading@10: int order, int n, int non_rec, int move_size) yading@10: { yading@10: float temp[MAX_BACKWARD_FILTER_ORDER+1]; yading@10: yading@10: do_hybrid_window(ractx, order, n, non_rec, temp, hist, rec, window); yading@10: yading@10: if (!compute_lpc_coefs(temp, order, lpc, 0, 1, 1)) yading@10: ractx->fdsp.vector_fmul(lpc, lpc, tab, FFALIGN(order, 16)); yading@10: yading@10: memmove(hist, hist + n, move_size*sizeof(*hist)); yading@10: } yading@10: yading@10: static int ra288_decode_frame(AVCodecContext * avctx, void *data, yading@10: int *got_frame_ptr, AVPacket *avpkt) yading@10: { yading@10: AVFrame *frame = data; yading@10: const uint8_t *buf = avpkt->data; yading@10: int buf_size = avpkt->size; yading@10: float *out; yading@10: int i, ret; yading@10: RA288Context *ractx = avctx->priv_data; yading@10: GetBitContext gb; yading@10: yading@10: if (buf_size < avctx->block_align) { yading@10: av_log(avctx, AV_LOG_ERROR, yading@10: "Error! Input buffer is too small [%d<%d]\n", yading@10: buf_size, avctx->block_align); yading@10: return AVERROR_INVALIDDATA; yading@10: } yading@10: yading@10: /* get output buffer */ yading@10: frame->nb_samples = RA288_BLOCK_SIZE * RA288_BLOCKS_PER_FRAME; yading@10: if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) yading@10: return ret; yading@10: out = (float *)frame->data[0]; yading@10: yading@10: init_get_bits(&gb, buf, avctx->block_align * 8); yading@10: yading@10: for (i=0; i < RA288_BLOCKS_PER_FRAME; i++) { yading@10: float gain = amptable[get_bits(&gb, 3)]; yading@10: int cb_coef = get_bits(&gb, 6 + (i&1)); yading@10: yading@10: decode(ractx, gain, cb_coef); yading@10: yading@10: memcpy(out, &ractx->sp_hist[70 + 36], RA288_BLOCK_SIZE * sizeof(*out)); yading@10: out += RA288_BLOCK_SIZE; yading@10: yading@10: if ((i & 7) == 3) { yading@10: backward_filter(ractx, ractx->sp_hist, ractx->sp_rec, syn_window, yading@10: ractx->sp_lpc, syn_bw_tab, 36, 40, 35, 70); yading@10: yading@10: backward_filter(ractx, ractx->gain_hist, ractx->gain_rec, gain_window, yading@10: ractx->gain_lpc, gain_bw_tab, 10, 8, 20, 28); yading@10: } yading@10: } yading@10: yading@10: *got_frame_ptr = 1; yading@10: yading@10: return avctx->block_align; yading@10: } yading@10: yading@10: AVCodec ff_ra_288_decoder = { yading@10: .name = "real_288", yading@10: .type = AVMEDIA_TYPE_AUDIO, yading@10: .id = AV_CODEC_ID_RA_288, yading@10: .priv_data_size = sizeof(RA288Context), yading@10: .init = ra288_decode_init, yading@10: .decode = ra288_decode_frame, yading@10: .capabilities = CODEC_CAP_DR1, yading@10: .long_name = NULL_IF_CONFIG_SMALL("RealAudio 2.0 (28.8K)"), yading@10: };