2 * Real Audio 1.0 (14.4K)
4 * Copyright (c) 2008 Vitor Sessak
5 * Copyright (c) 2003 Nick Kurshev
6 * Based on public domain decoder at http://www.honeypot.net/audio
8 * This file is part of FFmpeg.
10 * FFmpeg is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
13 * version 2.1 of the License, or (at your option) any later version.
15 * FFmpeg is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with FFmpeg; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 #include "libavutil/intmath.h"
31 static av_cold int ra144_decode_init(AVCodecContext * avctx)
33 RA144Context *ractx = avctx->priv_data;
37 ractx->lpc_coef[0] = ractx->lpc_tables[0];
38 ractx->lpc_coef[1] = ractx->lpc_tables[1];
40 avctx->sample_fmt = SAMPLE_FMT_S16;
44 static void do_output_subblock(RA144Context *ractx, const uint16_t *lpc_coefs,
45 int gval, GetBitContext *gb)
47 int cba_idx = get_bits(gb, 7); // index of the adaptive CB, 0 if none
48 int gain = get_bits(gb, 8);
49 int cb1_idx = get_bits(gb, 7);
50 int cb2_idx = get_bits(gb, 7);
52 ff_subblock_synthesis(ractx, lpc_coefs, cba_idx, cb1_idx, cb2_idx, gval,
56 /** Uncompress one block (20 bytes -> 160*2 bytes). */
57 static int ra144_decode_frame(AVCodecContext * avctx, void *vdata,
58 int *data_size, AVPacket *avpkt)
60 const uint8_t *buf = avpkt->data;
61 int buf_size = avpkt->size;
62 static const uint8_t sizes[10] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
63 unsigned int refl_rms[4]; // RMS of the reflection coefficients
64 uint16_t block_coefs[4][10]; // LPC coefficients of each sub-block
65 unsigned int lpc_refl[10]; // LPC reflection coefficients of the frame
67 int16_t *data = vdata;
70 RA144Context *ractx = avctx->priv_data;
73 if (*data_size < 2*160)
77 av_log(avctx, AV_LOG_ERROR,
78 "Frame too small (%d bytes). Truncated file?\n", buf_size);
82 init_get_bits(&gb, buf, 20 * 8);
85 lpc_refl[i] = ff_lpc_refl_cb[i][get_bits(&gb, sizes[i])];
87 ff_eval_coefs(ractx->lpc_coef[0], lpc_refl);
88 ractx->lpc_refl_rms[0] = ff_rms(lpc_refl);
90 energy = ff_energy_tab[get_bits(&gb, 5)];
92 refl_rms[0] = ff_interp(ractx, block_coefs[0], 1, 1, ractx->old_energy);
93 refl_rms[1] = ff_interp(ractx, block_coefs[1], 2,
94 energy <= ractx->old_energy,
95 ff_t_sqrt(energy*ractx->old_energy) >> 12);
96 refl_rms[2] = ff_interp(ractx, block_coefs[2], 3, 0, energy);
97 refl_rms[3] = ff_rescale_rms(ractx->lpc_refl_rms[0], energy);
99 ff_int_to_int16(block_coefs[3], ractx->lpc_coef[0]);
101 for (i=0; i < 4; i++) {
102 do_output_subblock(ractx, block_coefs[i], refl_rms[i], &gb);
104 for (j=0; j < BLOCKSIZE; j++)
105 *data++ = av_clip_int16(ractx->curr_sblock[j + 10] << 2);
108 ractx->old_energy = energy;
109 ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0];
111 FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]);
117 AVCodec ra_144_decoder =
122 sizeof(RA144Context),
127 .long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K)"),