| /* |
| * Real Audio 1.0 (14.4K) |
| * |
| * Copyright (c) 2008 Vitor Sessak |
| * Copyright (c) 2003 Nick Kurshev |
| * Based on public domain decoder at http://www.honeypot.net/audio |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "libavutil/intmath.h" |
| #include "avcodec.h" |
| #include "get_bits.h" |
| #include "ra144.h" |
| |
| |
| static av_cold int ra144_decode_init(AVCodecContext * avctx) |
| { |
| RA144Context *ractx = avctx->priv_data; |
| |
| ractx->avctx = avctx; |
| |
| ractx->lpc_coef[0] = ractx->lpc_tables[0]; |
| ractx->lpc_coef[1] = ractx->lpc_tables[1]; |
| |
| avctx->sample_fmt = AV_SAMPLE_FMT_S16; |
| return 0; |
| } |
| |
| static void do_output_subblock(RA144Context *ractx, const uint16_t *lpc_coefs, |
| int gval, GetBitContext *gb) |
| { |
| int cba_idx = get_bits(gb, 7); // index of the adaptive CB, 0 if none |
| int gain = get_bits(gb, 8); |
| int cb1_idx = get_bits(gb, 7); |
| int cb2_idx = get_bits(gb, 7); |
| |
| ff_subblock_synthesis(ractx, lpc_coefs, cba_idx, cb1_idx, cb2_idx, gval, |
| gain); |
| } |
| |
| /** Uncompress one block (20 bytes -> 160*2 bytes). */ |
| static int ra144_decode_frame(AVCodecContext * avctx, void *vdata, |
| int *data_size, AVPacket *avpkt) |
| { |
| const uint8_t *buf = avpkt->data; |
| int buf_size = avpkt->size; |
| static const uint8_t sizes[10] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2}; |
| unsigned int refl_rms[4]; // RMS of the reflection coefficients |
| uint16_t block_coefs[4][10]; // LPC coefficients of each sub-block |
| unsigned int lpc_refl[10]; // LPC reflection coefficients of the frame |
| int i, j; |
| int16_t *data = vdata; |
| unsigned int energy; |
| |
| RA144Context *ractx = avctx->priv_data; |
| GetBitContext gb; |
| |
| if (*data_size < 2*160) |
| return -1; |
| |
| if(buf_size < 20) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Frame too small (%d bytes). Truncated file?\n", buf_size); |
| *data_size = 0; |
| return buf_size; |
| } |
| init_get_bits(&gb, buf, 20 * 8); |
| |
| for (i=0; i<10; i++) |
| lpc_refl[i] = ff_lpc_refl_cb[i][get_bits(&gb, sizes[i])]; |
| |
| ff_eval_coefs(ractx->lpc_coef[0], lpc_refl); |
| ractx->lpc_refl_rms[0] = ff_rms(lpc_refl); |
| |
| energy = ff_energy_tab[get_bits(&gb, 5)]; |
| |
| refl_rms[0] = ff_interp(ractx, block_coefs[0], 1, 1, ractx->old_energy); |
| refl_rms[1] = ff_interp(ractx, block_coefs[1], 2, |
| energy <= ractx->old_energy, |
| ff_t_sqrt(energy*ractx->old_energy) >> 12); |
| refl_rms[2] = ff_interp(ractx, block_coefs[2], 3, 0, energy); |
| refl_rms[3] = ff_rescale_rms(ractx->lpc_refl_rms[0], energy); |
| |
| ff_int_to_int16(block_coefs[3], ractx->lpc_coef[0]); |
| |
| for (i=0; i < 4; i++) { |
| do_output_subblock(ractx, block_coefs[i], refl_rms[i], &gb); |
| |
| for (j=0; j < BLOCKSIZE; j++) |
| *data++ = av_clip_int16(ractx->curr_sblock[j + 10] << 2); |
| } |
| |
| ractx->old_energy = energy; |
| ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0]; |
| |
| FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]); |
| |
| *data_size = 2*160; |
| return 20; |
| } |
| |
| AVCodec ff_ra_144_decoder = |
| { |
| "real_144", |
| AVMEDIA_TYPE_AUDIO, |
| CODEC_ID_RA_144, |
| sizeof(RA144Context), |
| ra144_decode_init, |
| NULL, |
| NULL, |
| ra144_decode_frame, |
| .long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K)"), |
| }; |