3 * Copyright (c) 2007 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/channel_layout.h"
29 #include "libavutil/lfg.h"
33 #include "mpegaudiodsp.h"
39 static VLC band_vlc, scfi_vlc[2], dscf_vlc[2], res_vlc[2];
40 static VLC q1_vlc, q2_vlc[2], q3_vlc[2], quant_vlc[4][2], q9up_vlc;
42 static inline int mpc8_dec_base(GetBitContext *gb, int k, int n)
44 int len = mpc8_cnk_len[k-1][n-1] - 1;
45 int code = len ? get_bits_long(gb, len) : 0;
47 if (code >= mpc8_cnk_lost[k-1][n-1])
48 code = ((code << 1) | get_bits1(gb)) - mpc8_cnk_lost[k-1][n-1];
53 static inline int mpc8_dec_enum(GetBitContext *gb, int k, int n)
56 const uint32_t * C = mpc8_cnk[k-1];
57 int code = mpc8_dec_base(gb, k, n);
72 static inline int mpc8_get_mod_golomb(GetBitContext *gb, int m)
74 if(mpc8_cnk_len[0][m] < 1) return 0;
75 return mpc8_dec_base(gb, 1, m+1);
78 static int mpc8_get_mask(GetBitContext *gb, int size, int t)
83 mask = mpc8_dec_enum(gb, FFMIN(t, size - t), size);
84 if((t << 1) > size) mask = ~mask;
89 static av_cold void build_vlc(VLC *vlc, unsigned *buf_offset,
90 const uint8_t codes_counts[16],
91 const uint8_t **syms, int offset)
93 static VLC_TYPE vlc_buf[9296][2];
94 uint8_t len[MPC8_MAX_VLC_SIZE];
97 vlc->table = &vlc_buf[*buf_offset];
98 vlc->table_allocated = FF_ARRAY_ELEMS(vlc_buf) - *buf_offset;
100 for (int i = 16; i > 0; i--)
101 for (unsigned tmp = num + codes_counts[i - 1]; num < tmp; num++)
104 ff_init_vlc_from_lengths(vlc, FFMIN(len[0], 9), num, len, 1,
105 *syms, 1, 1, offset, INIT_VLC_STATIC_OVERLONG, NULL);
106 *buf_offset += vlc->table_size;
110 static av_cold int mpc8_decode_init(AVCodecContext * avctx)
113 MPCContext *c = avctx->priv_data;
115 static int vlc_initialized = 0;
116 const uint8_t *q_syms = mpc8_q_syms, *bands_syms = mpc8_bands_syms;
117 const uint8_t *res_syms = mpc8_res_syms, *scfi_syms = mpc8_scfi_syms;
118 const uint8_t *dscf_syms = mpc8_dscf_syms;
121 if(avctx->extradata_size < 2){
122 av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
125 memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
126 av_lfg_init(&c->rnd, 0xDEADBEEF);
127 ff_mpadsp_init(&c->mpadsp);
129 init_get_bits(&gb, avctx->extradata, 16);
131 skip_bits(&gb, 3);//sample rate
132 c->maxbands = get_bits(&gb, 5) + 1;
133 if (c->maxbands >= BANDS) {
134 av_log(avctx,AV_LOG_ERROR, "maxbands %d too high\n", c->maxbands);
135 return AVERROR_INVALIDDATA;
137 channels = get_bits(&gb, 4) + 1;
139 avpriv_request_sample(avctx, "Multichannel MPC SV8");
140 return AVERROR_PATCHWELCOME;
142 c->MSS = get_bits1(&gb);
143 c->frames = 1 << (get_bits(&gb, 3) * 2);
145 avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
146 avctx->channel_layout = (channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
147 avctx->channels = channels;
149 if(vlc_initialized) return 0;
150 av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
152 build_vlc(&band_vlc, &offset, mpc8_bands_len_counts, &bands_syms, 0);
154 build_vlc(&q1_vlc, &offset, mpc8_q1_len_counts, &q_syms, 0);
155 build_vlc(&q9up_vlc, &offset, mpc8_q9up_len_counts, &q_syms, 0);
157 for(i = 0; i < 2; i++){
158 build_vlc(&scfi_vlc[i], &offset, mpc8_scfi_len_counts[i], &scfi_syms, 0);
160 build_vlc(&dscf_vlc[i], &offset, mpc8_dscf_len_counts[i], &dscf_syms, 0);
162 build_vlc(&res_vlc[i], &offset, mpc8_res_len_counts[i], &res_syms, 0);
164 build_vlc(&q2_vlc[i], &offset, mpc8_q2_len_counts[i], &q_syms, 0);
165 build_vlc(&q3_vlc[i], &offset, mpc8_q34_len_counts[i],
166 &q_syms, -48 - 16 * i);
167 for (int j = 0; j < 4; j++)
168 build_vlc(&quant_vlc[j][i], &offset, mpc8_q5_8_len_counts[i][j],
169 &q_syms, -((8 << j) - 1));
172 ff_mpa_synth_init_fixed();
177 static int mpc8_decode_frame(AVCodecContext * avctx, void *data,
178 int *got_frame_ptr, AVPacket *avpkt)
180 AVFrame *frame = data;
181 const uint8_t *buf = avpkt->data;
182 int buf_size = avpkt->size;
183 MPCContext *c = avctx->priv_data;
184 GetBitContext gb2, *gb = &gb2;
185 int i, j, k, ch, cnt, res, t;
186 Band *bands = c->bands;
188 int maxband, keyframe;
191 keyframe = c->cur_frame == 0;
194 memset(c->Q, 0, sizeof(c->Q));
195 c->last_bits_used = 0;
197 if ((res = init_get_bits8(gb, buf, buf_size)) < 0)
200 skip_bits(gb, c->last_bits_used & 7);
203 maxband = mpc8_get_mod_golomb(gb, c->maxbands + 1);
205 maxband = c->last_max_band + get_vlc2(gb, band_vlc.table, MPC8_BANDS_BITS, 2);
206 if(maxband > 32) maxband -= 33;
209 if (get_bits_left(gb) < 0) {
214 if(maxband > c->maxbands + 1) {
215 av_log(avctx, AV_LOG_ERROR, "maxband %d too large\n",maxband);
216 return AVERROR_INVALIDDATA;
218 c->last_max_band = maxband;
220 /* read subband indexes */
222 last[0] = last[1] = 0;
223 for(i = maxband - 1; i >= 0; i--){
224 for(ch = 0; ch < 2; ch++){
225 last[ch] = get_vlc2(gb, res_vlc[last[ch] > 2].table, MPC8_RES_BITS, 2) + last[ch];
226 if(last[ch] > 15) last[ch] -= 17;
227 bands[i].res[ch] = last[ch];
234 for(i = 0; i < maxband; i++)
235 if(bands[i].res[0] || bands[i].res[1])
237 t = mpc8_get_mod_golomb(gb, cnt);
238 mask = mpc8_get_mask(gb, cnt, t);
239 for(i = maxband - 1; i >= 0; i--)
240 if(bands[i].res[0] || bands[i].res[1]){
241 bands[i].msf = mask & 1;
246 for(i = maxband; i < c->maxbands; i++)
247 bands[i].res[0] = bands[i].res[1] = 0;
250 for(i = 0; i < 32; i++)
251 c->oldDSCF[0][i] = c->oldDSCF[1][i] = 1;
254 for(i = 0; i < maxband; i++){
255 if(bands[i].res[0] || bands[i].res[1]){
256 cnt = !!bands[i].res[0] + !!bands[i].res[1] - 1;
258 t = get_vlc2(gb, scfi_vlc[cnt].table, scfi_vlc[cnt].bits, 1);
259 if(bands[i].res[0]) bands[i].scfi[0] = t >> (2 * cnt);
260 if(bands[i].res[1]) bands[i].scfi[1] = t & 3;
265 for(i = 0; i < maxband; i++){
266 for(ch = 0; ch < 2; ch++){
267 if(!bands[i].res[ch]) continue;
269 if(c->oldDSCF[ch][i]){
270 bands[i].scf_idx[ch][0] = get_bits(gb, 7) - 6;
271 c->oldDSCF[ch][i] = 0;
273 t = get_vlc2(gb, dscf_vlc[1].table, MPC8_DSCF1_BITS, 2);
275 t += get_bits(gb, 6);
276 bands[i].scf_idx[ch][0] = ((bands[i].scf_idx[ch][2] + t - 25) & 0x7F) - 6;
278 for(j = 0; j < 2; j++){
279 if((bands[i].scfi[ch] << j) & 2)
280 bands[i].scf_idx[ch][j + 1] = bands[i].scf_idx[ch][j];
282 t = get_vlc2(gb, dscf_vlc[0].table, MPC8_DSCF0_BITS, 2);
284 t = 64 + get_bits(gb, 6);
285 bands[i].scf_idx[ch][j + 1] = ((bands[i].scf_idx[ch][j] + t - 25) & 0x7F) - 6;
291 for(i = 0, off = 0; i < maxband; i++, off += SAMPLES_PER_BAND){
292 for(ch = 0; ch < 2; ch++){
293 res = bands[i].res[ch];
296 for(j = 0; j < SAMPLES_PER_BAND; j++)
297 c->Q[ch][off + j] = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
302 for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){
303 cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2);
304 t = mpc8_get_mask(gb, 18, cnt);
305 for(k = 0; k < SAMPLES_PER_BAND / 2; k++)
306 c->Q[ch][off + j + k] = t & (1 << (SAMPLES_PER_BAND / 2 - k - 1))
307 ? (get_bits1(gb) << 1) - 1 : 0;
311 cnt = 6;//2*mpc8_thres[res]
312 for(j = 0; j < SAMPLES_PER_BAND; j += 3){
313 t = get_vlc2(gb, q2_vlc[cnt > 3].table, MPC8_Q2_BITS, 2);
314 c->Q[ch][off + j + 0] = mpc8_idx50[t];
315 c->Q[ch][off + j + 1] = mpc8_idx51[t];
316 c->Q[ch][off + j + 2] = mpc8_idx52[t];
317 cnt = (cnt >> 1) + mpc8_huffq2[t];
322 for(j = 0; j < SAMPLES_PER_BAND; j += 2){
323 t = get_vlc2(gb, q3_vlc[res - 3].table, MPC8_Q3_BITS, 2);
324 c->Q[ch][off + j + 1] = t >> 4;
325 c->Q[ch][off + j + 0] = sign_extend(t, 4);
332 cnt = 2 * mpc8_thres[res];
333 for(j = 0; j < SAMPLES_PER_BAND; j++){
334 const VLC *vlc = &quant_vlc[res - 5][cnt > mpc8_thres[res]];
335 c->Q[ch][off + j] = get_vlc2(gb, vlc->table, vlc->bits, 2);
336 cnt = (cnt >> 1) + FFABS(c->Q[ch][off + j]);
340 for(j = 0; j < SAMPLES_PER_BAND; j++){
341 c->Q[ch][off + j] = get_vlc2(gb, q9up_vlc.table, MPC8_Q9UP_BITS, 2);
343 c->Q[ch][off + j] <<= res - 9;
344 c->Q[ch][off + j] |= get_bits(gb, res - 9);
346 c->Q[ch][off + j] -= (1 << (res - 2)) - 1;
352 frame->nb_samples = MPC_FRAME_SIZE;
353 if ((res = ff_get_buffer(avctx, frame, 0)) < 0)
356 ff_mpc_dequantize_and_synth(c, maxband - 1,
357 (int16_t **)frame->extended_data,
362 c->last_bits_used = get_bits_count(gb);
363 if(c->cur_frame >= c->frames)
365 if (get_bits_left(gb) < 0) {
366 av_log(avctx, AV_LOG_ERROR, "Overread %d\n", -get_bits_left(gb));
367 c->last_bits_used = buf_size << 3;
368 } else if (c->cur_frame == 0 && get_bits_left(gb) < 8) {// we have only padding left
369 c->last_bits_used = buf_size << 3;
374 return c->cur_frame ? c->last_bits_used >> 3 : buf_size;
377 static av_cold void mpc8_decode_flush(AVCodecContext *avctx)
379 MPCContext *c = avctx->priv_data;
383 AVCodec ff_mpc8_decoder = {
385 .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
386 .type = AVMEDIA_TYPE_AUDIO,
387 .id = AV_CODEC_ID_MUSEPACK8,
388 .priv_data_size = sizeof(MPCContext),
389 .init = mpc8_decode_init,
390 .decode = mpc8_decode_frame,
391 .flush = mpc8_decode_flush,
392 .capabilities = AV_CODEC_CAP_DR1,
393 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
394 AV_SAMPLE_FMT_NONE },