1/* 2 * Real Audio 1.0 (14.4K) 3 * 4 * Copyright (c) 2008 Vitor Sessak 5 * Copyright (c) 2003 Nick Kurshev 6 * Based on public domain decoder at http://www.honeypot.net/audio 7 * 8 * This file is part of FFmpeg. 9 * 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. 14 * 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. 19 * 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 23 */ 24 25#include "libavutil/channel_layout.h" 26#include "avcodec.h" 27#include "codec_internal.h" 28#include "get_bits.h" 29#include "internal.h" 30#include "ra144.h" 31 32 33static av_cold int ra144_decode_init(AVCodecContext * avctx) 34{ 35 RA144Context *ractx = avctx->priv_data; 36 37 ractx->avctx = avctx; 38 ff_audiodsp_init(&ractx->adsp); 39 40 ractx->lpc_coef[0] = ractx->lpc_tables[0]; 41 ractx->lpc_coef[1] = ractx->lpc_tables[1]; 42 43 av_channel_layout_uninit(&avctx->ch_layout); 44 avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO; 45 avctx->sample_fmt = AV_SAMPLE_FMT_S16; 46 47 return 0; 48} 49 50static void do_output_subblock(RA144Context *ractx, const int16_t *lpc_coefs, 51 int gval, GetBitContext *gb) 52{ 53 int cba_idx = get_bits(gb, 7); // index of the adaptive CB, 0 if none 54 int gain = get_bits(gb, 8); 55 int cb1_idx = get_bits(gb, 7); 56 int cb2_idx = get_bits(gb, 7); 57 58 ff_subblock_synthesis(ractx, lpc_coefs, cba_idx, cb1_idx, cb2_idx, gval, 59 gain); 60} 61 62/** Uncompress one block (20 bytes -> 160*2 bytes). */ 63static int ra144_decode_frame(AVCodecContext * avctx, AVFrame *frame, 64 int *got_frame_ptr, AVPacket *avpkt) 65{ 66 const uint8_t *buf = avpkt->data; 67 int buf_size = avpkt->size; 68 static const uint8_t sizes[LPC_ORDER] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2}; 69 unsigned int refl_rms[NBLOCKS]; // RMS of the reflection coefficients 70 int16_t block_coefs[NBLOCKS][LPC_ORDER]; // LPC coefficients of each sub-block 71 unsigned int lpc_refl[LPC_ORDER]; // LPC reflection coefficients of the frame 72 int i, j; 73 int ret; 74 int16_t *samples; 75 unsigned int energy; 76 77 RA144Context *ractx = avctx->priv_data; 78 GetBitContext gb; 79 80 if (buf_size < FRAME_SIZE) { 81 av_log(avctx, AV_LOG_ERROR, 82 "Frame too small (%d bytes). Truncated file?\n", buf_size); 83 *got_frame_ptr = 0; 84 return AVERROR_INVALIDDATA; 85 } 86 87 /* get output buffer */ 88 frame->nb_samples = NBLOCKS * BLOCKSIZE; 89 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 90 return ret; 91 samples = (int16_t *)frame->data[0]; 92 93 init_get_bits8(&gb, buf, FRAME_SIZE); 94 95 for (i = 0; i < LPC_ORDER; i++) 96 lpc_refl[i] = ff_lpc_refl_cb[i][get_bits(&gb, sizes[i])]; 97 98 ff_eval_coefs(ractx->lpc_coef[0], lpc_refl); 99 ractx->lpc_refl_rms[0] = ff_rms(lpc_refl); 100 101 energy = ff_energy_tab[get_bits(&gb, 5)]; 102 103 refl_rms[0] = ff_interp(ractx, block_coefs[0], 1, 1, ractx->old_energy); 104 refl_rms[1] = ff_interp(ractx, block_coefs[1], 2, 105 energy <= ractx->old_energy, 106 ff_t_sqrt(energy*ractx->old_energy) >> 12); 107 refl_rms[2] = ff_interp(ractx, block_coefs[2], 3, 0, energy); 108 refl_rms[3] = ff_rescale_rms(ractx->lpc_refl_rms[0], energy); 109 110 ff_int_to_int16(block_coefs[3], ractx->lpc_coef[0]); 111 112 for (i=0; i < NBLOCKS; i++) { 113 do_output_subblock(ractx, block_coefs[i], refl_rms[i], &gb); 114 115 for (j=0; j < BLOCKSIZE; j++) 116 *samples++ = av_clip_int16(ractx->curr_sblock[j + 10] * (1 << 2)); 117 } 118 119 ractx->old_energy = energy; 120 ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0]; 121 122 FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]); 123 124 *got_frame_ptr = 1; 125 126 return FRAME_SIZE; 127} 128 129const FFCodec ff_ra_144_decoder = { 130 .p.name = "real_144", 131 .p.long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K)"), 132 .p.type = AVMEDIA_TYPE_AUDIO, 133 .p.id = AV_CODEC_ID_RA_144, 134 .priv_data_size = sizeof(RA144Context), 135 .init = ra144_decode_init, 136 FF_CODEC_DECODE_CB(ra144_decode_frame), 137 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF, 138 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 139}; 140