2 * ViewQuest VQC decoder
3 * Copyright (C) 2022 Peter Ross
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 #include "codec_internal.h"
26 #include "libavutil/thread.h"
28 #define VECTOR_VLC_BITS 6
30 static const uint8_t vector_nbits[] = {
31 2, 4, 4, 4, 4, 2, 4, 4,
32 6, 6, 6, 6, 6, 6, 6, 6
45 /* vector symbols are signed, but returned unsigned by get_vlc2()
46 codebook indexes are cast as uint8_t in seed_codebook() to compensate */
47 static const int8_t vector_symbols[] = {
48 0, SKIP_3, SKIP_4, SKIP_5, SKIP_6, STOP_RUN, 1, -1,
49 2, 3, 4, SIGNED_8BIT, -2, -3, -4, SIGNED_6BIT
52 static VLC vector_vlc;
54 static av_cold void vqc_init_static_data(void)
56 VLC_INIT_STATIC_FROM_LENGTHS(&vector_vlc, VECTOR_VLC_BITS, FF_ARRAY_ELEMS(vector_nbits),
59 0, 0, 1 << VECTOR_VLC_BITS);
62 typedef struct VqcContext {
65 int16_t * coeff, *tmp1, *tmp2;
66 int16_t codebook[4][256];
69 static av_cold int vqc_decode_init(AVCodecContext * avctx)
71 static AVOnce init_static_once = AV_ONCE_INIT;
72 VqcContext *s = avctx->priv_data;
74 if (avctx->width & 15)
75 return AVERROR_PATCHWELCOME;
77 s->vectors = av_malloc((avctx->width * avctx->height * 3) / 2);
79 return AVERROR(ENOMEM);
81 s->coeff = av_malloc_array(2 * avctx->width, sizeof(s->coeff[0]));
83 return AVERROR(ENOMEM);
85 s->tmp1 = av_malloc_array(avctx->width / 2, sizeof(s->tmp1[0]));
87 return AVERROR(ENOMEM);
89 s->tmp2 = av_malloc_array(avctx->width / 2, sizeof(s->tmp2[0]));
91 return AVERROR(ENOMEM);
93 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
94 s->frame = av_frame_alloc();
96 return AVERROR(ENOMEM);
98 ff_thread_once(&init_static_once, vqc_init_static_data);
103 static int seed_pow1(int x)
105 return x >= 1 && x <= 5 ? 1 << x : 0;
108 static int seed_pow2(int x)
110 return x >= 1 && x <= 4 ? 1 << x : 1;
113 static int bias(int x, int c)
123 static void seed_codebooks(VqcContext * s, const int * seed)
125 int book1 = -256 * seed[3];
126 int book2 = -128 * seed[4];
127 int book3 = -128 * seed[5];
128 int book4 = -128 * seed[6];
130 for (int i = -128; i < 128; i++) {
131 s->codebook[0][(uint8_t)i] = book1;
132 s->codebook[1][(uint8_t)i] = bias(book2, seed[0]);
133 s->codebook[2][(uint8_t)i] = bias(book3, seed[1]);
134 s->codebook[3][(uint8_t)i] = bias(book4, seed[2]);
136 book1 += 2 * seed[3];
143 static int decode_vectors(VqcContext * s, const uint8_t * buf, int size, int width, int height)
146 uint8_t * vectors = s->vectors;
147 uint8_t * vectors_end = s->vectors + (width * height * 3) / 2;
149 memset(vectors, 0, 3 * width * height / 2);
151 init_get_bits8(&gb, buf, size);
153 for (int i = 0; i < 3 * width * height / 2 / 32; i++) {
154 uint8_t * dst = vectors;
157 *dst++ = get_bits(&gb, 8);
158 *dst++ = get_bits(&gb, 8);
160 while (show_bits(&gb, 2) != 2) {
161 if (dst >= vectors_end - 1)
164 if (get_bits_left(&gb) < 4)
165 return AVERROR_INVALIDDATA;
167 if (!show_bits(&gb, 4)) {
174 symbol = get_vlc2(&gb, vector_vlc.table, VECTOR_VLC_BITS, 1);
176 case SKIP_3: dst += 3; break;
177 case SKIP_4: dst += 4; break;
178 case SKIP_5: dst += 5; break;
179 case SKIP_6: dst += 6; break;
180 case SIGNED_8BIT: *dst++ = get_sbits(&gb, 8); break;
181 case SIGNED_6BIT: *dst++ = get_sbits(&gb, 6); break;
194 static void load_coeffs(VqcContext * s, const uint8_t * v, int width, int coeff_width)
196 int16_t * c0 = s->coeff;
197 int16_t * c1 = s->coeff + coeff_width;
198 int16_t * c0_125 = s->coeff + (coeff_width >> 3);
199 int16_t * c1_125 = s->coeff + coeff_width + (coeff_width >> 3);
200 int16_t * c0_25 = s->coeff + (coeff_width >> 2);
201 int16_t * c1_25 = s->coeff + coeff_width + (coeff_width >> 2);
202 int16_t * c0_5 = s->coeff + (coeff_width >> 1);
203 int16_t * c1_5 = s->coeff + coeff_width + (coeff_width >> 1);
205 for (int i = 0; i < width; i++) {
206 c0[0] = s->codebook[0][v[0]];
207 c0[1] = s->codebook[0][v[1]];
210 c1[0] = s->codebook[0][v[2]];
211 c1[1] = s->codebook[0][v[3]];
214 c0_125[0] = s->codebook[1][v[4]];
215 c0_125[1] = s->codebook[1][v[5]];
218 c1_125[0] = s->codebook[1][v[6]];
219 c1_125[1] = s->codebook[1][v[7]];
222 c0_25[0] = s->codebook[2][v[8]];
223 c0_25[1] = s->codebook[2][v[9]];
224 c0_25[2] = s->codebook[2][v[10]];
225 c0_25[3] = s->codebook[2][v[11]];
228 c1_25[0] = s->codebook[2][v[12]];
229 c1_25[1] = s->codebook[2][v[13]];
230 c1_25[2] = s->codebook[2][v[14]];
231 c1_25[3] = s->codebook[2][v[15]];
234 if (v[16] | v[17] | v[18] | v[19]) {
235 c0_5[0] = s->codebook[3][v[16]];
236 c0_5[1] = s->codebook[3][v[17]];
237 c0_5[2] = s->codebook[3][v[18]];
238 c0_5[3] = s->codebook[3][v[19]];
240 c0_5[0] = c0_5[1] = c0_5[2] = c0_5[3] = 0;
243 if (v[20] | v[21] | v[22] | v[23]) {
244 c0_5[4] = s->codebook[3][v[20]];
245 c0_5[5] = s->codebook[3][v[21]];
246 c0_5[6] = s->codebook[3][v[22]];
247 c0_5[7] = s->codebook[3][v[23]];
249 c0_5[4] = c0_5[5] = c0_5[6] = c0_5[7] = 0;
253 if (v[24] | v[25] | v[26] | v[27]) {
254 c1_5[0] = s->codebook[3][v[24]];
255 c1_5[1] = s->codebook[3][v[25]];
256 c1_5[2] = s->codebook[3][v[26]];
257 c1_5[3] = s->codebook[3][v[27]];
259 c1_5[0] = c1_5[1] = c1_5[2] = c1_5[3] = 0;
262 if (v[28] | v[29] | v[30] | v[31]) {
263 c1_5[4] = s->codebook[3][v[28]];
264 c1_5[5] = s->codebook[3][v[29]];
265 c1_5[6] = s->codebook[3][v[30]];
266 c1_5[7] = s->codebook[3][v[31]];
268 c1_5[4] = c1_5[5] = c1_5[6] = c1_5[7] = 0;
276 static void transform1(const int16_t * a, const int16_t * b, int16_t * dst, int width)
278 int s0 = a[0] + (b[0] >> 1);
280 for (int i = 0; i < width / 2 - 1; i++) {
282 s0 = a[i + 1] + ((b[i] + b[i + 1]) >> 1);
283 dst[i * 2 + 1] = ((dst[i * 2] + s0) >> 1) - 2 * b[i];
287 dst[width - 1] = a[width / 2 - 1] + ((b[width / 2 - 2] - 2 * b[width / 2 - 1]) >> 2) - b[width / 2 - 1];
290 static uint8_t clip(int x)
292 return x >= -128 ? x <= 127 ? x + 0x80 : 0x00 : 0xFF;
295 static void transform2(const int16_t * a, const int16_t * b, uint8_t * dst, int width)
297 int s0 = a[0] + (b[0] >> 1);
300 for (int i = 0; i < width / 2 - 1; i++) {
301 dst[i * 2] = av_clip_uint8(s0 + 0x80);
302 tmp = a[i + 1] + ((b[i] + b[i + 1]) >> 1);
303 dst[i * 2 + 1] = av_clip_uint8(((tmp + s0) >> 1) - 2 * b[i] + 0x80);
307 dst[width - 2] = clip(s0);
308 dst[width - 1] = clip(a[width / 2 - 1] + ((b[width / 2 - 2] - 2 * b[width / 2 - 1]) >> 2) - b[width / 2 - 1]);
311 static void decode_strip(VqcContext * s, uint8_t * dst, int stride, int width)
313 const int16_t * coeff;
315 for (int i = 0; i < width; i++) {
316 int v0 = s->coeff[i];
317 int v1 = s->coeff[width + i];
318 s->coeff[i] = v0 - v1;
319 s->coeff[width + i] = v0 + v1;
324 transform1(coeff, coeff + width / 8, s->tmp1, width / 4);
325 transform1(s->tmp1, coeff + width / 4, s->tmp2, width / 2);
326 transform2(s->tmp2, coeff + width / 2, dst, width);
331 transform1(coeff, coeff + width / 8, s->tmp1, width / 4);
332 transform1(s->tmp1, coeff + width / 4, s->tmp2, width / 2);
333 transform2(s->tmp2, coeff + width / 2, dst, width);
336 static void decode_frame(VqcContext * s, int width, int height)
338 uint8_t * vectors = s->vectors;
339 uint8_t * y = s->frame->data[0];
340 uint8_t * u = s->frame->data[1];
341 uint8_t * v = s->frame->data[2];
343 for (int j = 0; j < height / 4; j++) {
344 load_coeffs(s, vectors, width / 16, width);
345 decode_strip(s, y, s->frame->linesize[0], width);
346 vectors += 2 * width;
347 y += 2 * s->frame->linesize[0];
349 load_coeffs(s, vectors, width / 32, width / 2);
350 decode_strip(s, u, s->frame->linesize[1], width / 2);
352 u += 2 * s->frame->linesize[1];
354 load_coeffs(s, vectors, width / 16, width);
355 decode_strip(s, y, s->frame->linesize[0], width);
356 vectors += 2 * width;
357 y += 2 * s->frame->linesize[0];
359 load_coeffs(s, vectors, width / 32, width / 2);
360 decode_strip(s, v, s->frame->linesize[2], width / 2);
362 v += 2 * s->frame->linesize[2];
366 static int vqc_decode_frame(AVCodecContext *avctx, AVFrame * rframe,
367 int * got_frame, AVPacket * avpkt)
369 VqcContext *s = avctx->priv_data;
371 const uint8_t * buf = avpkt->data;
372 int cache, seed[7], gamma, contrast;
375 return AVERROR_INVALIDDATA;
377 if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
380 av_log(avctx, AV_LOG_DEBUG, "VQC%d format\n", (buf[2] & 1) + 1);
382 if (((buf[0] >> 1) & 7) != 5) {
383 avpriv_request_sample(avctx, "subversion != 5\n");
384 return AVERROR_PATCHWELCOME;
387 cache = AV_RL24(buf + 4);
388 seed[2] = seed_pow1((cache >> 1) & 7);
389 seed[1] = seed_pow1((cache >> 4) & 7);
390 seed[0] = seed_pow1((cache >> 7) & 7);
391 seed[6] = seed_pow2((cache >> 10) & 7);
392 seed[5] = seed_pow2((cache >> 13) & 7);
393 seed[4] = seed_pow2((cache >> 16) & 7);
394 seed[3] = seed_pow2((cache >> 19) & 7);
397 contrast = AV_RL16(buf + 2) >> 1;
398 if (gamma || contrast)
399 avpriv_request_sample(avctx, "gamma=0x%x, contrast=0x%x\n", gamma, contrast);
401 seed_codebooks(s, seed);
402 ret = decode_vectors(s, buf + 7, avpkt->size - 7, avctx->width, avctx->height);
405 decode_frame(s, avctx->width, avctx->height);
407 if ((ret = av_frame_ref(rframe, s->frame)) < 0)
415 static av_cold int vqc_decode_end(AVCodecContext * avctx)
417 VqcContext *s = avctx->priv_data;
419 av_freep(&s->vectors);
423 av_frame_free(&s->frame);
428 const FFCodec ff_vqc_decoder = {
430 CODEC_LONG_NAME("ViewQuest VQC"),
431 .p.type = AVMEDIA_TYPE_VIDEO,
432 .p.id = AV_CODEC_ID_VQC,
433 .priv_data_size = sizeof(VqcContext),
434 .init = vqc_decode_init,
435 .close = vqc_decode_end,
436 FF_CODEC_DECODE_CB(vqc_decode_frame),
437 .p.capabilities = AV_CODEC_CAP_DR1,
438 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,