3 * Copyright (c) 2006 Konstantin Shishkov
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
25 * divided into 32 subbands.
28 #include "libavutil/lfg.h"
32 #include "mpegaudiodsp.h"
33 #include "libavutil/audioconvert.h"
39 #define SAMPLES_PER_BAND 36
40 #define MPC_FRAME_SIZE (BANDS * SAMPLES_PER_BAND)
42 static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2];
44 static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] =
46 0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124,
47 5636, 6164, 6676, 7224
51 static av_cold int mpc7_decode_init(AVCodecContext * avctx)
54 MPCContext *c = avctx->priv_data;
57 static int vlc_initialized = 0;
59 static VLC_TYPE scfi_table[1 << MPC7_SCFI_BITS][2];
60 static VLC_TYPE dscf_table[1 << MPC7_DSCF_BITS][2];
61 static VLC_TYPE hdr_table[1 << MPC7_HDR_BITS][2];
62 static VLC_TYPE quant_tables[7224][2];
64 if(avctx->extradata_size < 16){
65 av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
68 memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
69 av_lfg_init(&c->rnd, 0xDEADBEEF);
70 dsputil_init(&c->dsp, avctx);
71 ff_mpadsp_init(&c->mpadsp);
72 c->dsp.bswap_buf((uint32_t*)buf, (const uint32_t*)avctx->extradata, 4);
74 init_get_bits(&gb, buf, 128);
76 c->IS = get_bits1(&gb);
77 c->MSS = get_bits1(&gb);
78 c->maxbands = get_bits(&gb, 6);
79 if(c->maxbands >= BANDS){
80 av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands);
83 skip_bits_long(&gb, 88);
84 c->gapless = get_bits1(&gb);
85 c->lastframelen = get_bits(&gb, 11);
86 av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n",
87 c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands);
88 c->frames_to_skip = 0;
90 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
91 avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
93 if(vlc_initialized) return 0;
94 av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
95 scfi_vlc.table = scfi_table;
96 scfi_vlc.table_allocated = 1 << MPC7_SCFI_BITS;
97 if(init_vlc(&scfi_vlc, MPC7_SCFI_BITS, MPC7_SCFI_SIZE,
99 &mpc7_scfi[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
100 av_log(avctx, AV_LOG_ERROR, "Cannot init SCFI VLC\n");
103 dscf_vlc.table = dscf_table;
104 dscf_vlc.table_allocated = 1 << MPC7_DSCF_BITS;
105 if(init_vlc(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE,
107 &mpc7_dscf[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
108 av_log(avctx, AV_LOG_ERROR, "Cannot init DSCF VLC\n");
111 hdr_vlc.table = hdr_table;
112 hdr_vlc.table_allocated = 1 << MPC7_HDR_BITS;
113 if(init_vlc(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE,
115 &mpc7_hdr[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
116 av_log(avctx, AV_LOG_ERROR, "Cannot init HDR VLC\n");
119 for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){
120 for(j = 0; j < 2; j++){
121 quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]];
122 quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j];
123 if(init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],
124 &mpc7_quant_vlc[i][j][1], 4, 2,
125 &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC)){
126 av_log(avctx, AV_LOG_ERROR, "Cannot init QUANT VLC %i,%i\n",i,j);
136 * Fill samples for given subband
138 static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)
143 for(i = 0; i < SAMPLES_PER_BAND; i++){
144 *dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
149 for(i = 0; i < SAMPLES_PER_BAND/3; i++){
150 t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);
151 *dst++ = mpc7_idx30[t];
152 *dst++ = mpc7_idx31[t];
153 *dst++ = mpc7_idx32[t];
158 for(i = 0; i < SAMPLES_PER_BAND/2; i++){
159 t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);
160 *dst++ = mpc7_idx50[t];
161 *dst++ = mpc7_idx51[t];
164 case 3: case 4: case 5: case 6: case 7:
166 for(i = 0; i < SAMPLES_PER_BAND; i++)
167 *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];
169 case 8: case 9: case 10: case 11: case 12:
170 case 13: case 14: case 15: case 16: case 17:
171 t = (1 << (idx - 2)) - 1;
172 for(i = 0; i < SAMPLES_PER_BAND; i++)
173 *dst++ = get_bits(gb, idx - 1) - t;
175 default: // case 0 and -2..-17
180 static int get_scale_idx(GetBitContext *gb, int ref)
182 int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;
184 return get_bits(gb, 6);
188 static int mpc7_decode_frame(AVCodecContext * avctx,
189 void *data, int *data_size,
192 const uint8_t *buf = avpkt->data;
193 int buf_size = avpkt->size;
194 MPCContext *c = avctx->priv_data;
199 Band *bands = c->bands;
201 int bits_used, bits_avail;
203 memset(bands, 0, sizeof(bands));
205 av_log(avctx, AV_LOG_ERROR, "Too small buffer passed (%i bytes)\n", buf_size);
208 bits = av_malloc(((buf_size - 1) & ~3) + FF_INPUT_BUFFER_PADDING_SIZE);
209 c->dsp.bswap_buf((uint32_t*)bits, (const uint32_t*)(buf + 4), (buf_size - 4) >> 2);
210 init_get_bits(&gb, bits, (buf_size - 4)* 8);
211 skip_bits_long(&gb, buf[0]);
213 /* read subband indexes */
214 for(i = 0; i <= c->maxbands; i++){
215 for(ch = 0; ch < 2; ch++){
217 if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;
218 if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);
219 else bands[i].res[ch] = bands[i-1].res[ch] + t;
222 if(bands[i].res[0] || bands[i].res[1]){
224 if(c->MSS) bands[i].msf = get_bits1(&gb);
227 /* get scale indexes coding method */
228 for(i = 0; i <= mb; i++)
229 for(ch = 0; ch < 2; ch++)
230 if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);
231 /* get scale indexes */
232 for(i = 0; i <= mb; i++){
233 for(ch = 0; ch < 2; ch++){
234 if(bands[i].res[ch]){
235 bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];
236 bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]);
237 switch(bands[i].scfi[ch]){
239 bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
240 bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
243 bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
244 bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];
247 bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
248 bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
251 bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
254 c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];
259 memset(c->Q, 0, sizeof(c->Q));
261 for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)
262 for(ch = 0; ch < 2; ch++)
263 idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);
265 ff_mpc_dequantize_and_synth(c, mb, data, 2);
269 bits_used = get_bits_count(&gb);
270 bits_avail = (buf_size - 4) * 8;
271 if(!buf[1] && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))){
272 av_log(NULL,0, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);
275 if(c->frames_to_skip){
280 *data_size = (buf[1] ? c->lastframelen : MPC_FRAME_SIZE) * 4;
285 static void mpc7_decode_flush(AVCodecContext *avctx)
287 MPCContext *c = avctx->priv_data;
289 memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
290 c->frames_to_skip = 32;
293 AVCodec ff_mpc7_decoder = {
302 .flush = mpc7_decode_flush,
303 .long_name = NULL_IF_CONFIG_SMALL("Musepack SV7"),