blob: 3eed17c0dae75eaa1e6d4e6bc095ff6d9c206e41
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 "get_bits.h" |
28 | #include "internal.h" |
29 | #include "ra144.h" |
30 | |
31 | |
32 | static av_cold int ra144_decode_init(AVCodecContext * avctx) |
33 | { |
34 | RA144Context *ractx = avctx->priv_data; |
35 | |
36 | ractx->avctx = avctx; |
37 | ff_audiodsp_init(&ractx->adsp); |
38 | |
39 | ractx->lpc_coef[0] = ractx->lpc_tables[0]; |
40 | ractx->lpc_coef[1] = ractx->lpc_tables[1]; |
41 | |
42 | avctx->channels = 1; |
43 | avctx->channel_layout = AV_CH_LAYOUT_MONO; |
44 | avctx->sample_fmt = AV_SAMPLE_FMT_S16; |
45 | |
46 | return 0; |
47 | } |
48 | |
49 | static void do_output_subblock(RA144Context *ractx, const int16_t *lpc_coefs, |
50 | int gval, GetBitContext *gb) |
51 | { |
52 | int cba_idx = get_bits(gb, 7); // index of the adaptive CB, 0 if none |
53 | int gain = get_bits(gb, 8); |
54 | int cb1_idx = get_bits(gb, 7); |
55 | int cb2_idx = get_bits(gb, 7); |
56 | |
57 | ff_subblock_synthesis(ractx, lpc_coefs, cba_idx, cb1_idx, cb2_idx, gval, |
58 | gain); |
59 | } |
60 | |
61 | /** Uncompress one block (20 bytes -> 160*2 bytes). */ |
62 | static int ra144_decode_frame(AVCodecContext * avctx, void *data, |
63 | int *got_frame_ptr, AVPacket *avpkt) |
64 | { |
65 | AVFrame *frame = data; |
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] << 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 | |
129 | AVCodec ff_ra_144_decoder = { |
130 | .name = "real_144", |
131 | .long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K)"), |
132 | .type = AVMEDIA_TYPE_AUDIO, |
133 | .id = AV_CODEC_ID_RA_144, |
134 | .priv_data_size = sizeof(RA144Context), |
135 | .init = ra144_decode_init, |
136 | .decode = ra144_decode_frame, |
137 | .capabilities = AV_CODEC_CAP_DR1, |
138 | }; |
139 |