2 * Microsoft Screen 2 (aka Windows Media Video V9 Screen) decoder
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * Microsoft Screen 2 (aka Windows Media Video V9 Screen) decoder
26 #include "libavutil/avassert.h"
27 #include "error_resilience.h"
29 #include "msmpeg4data.h"
35 typedef struct MSS2Context {
45 static void arith2_normalise(ArithCoder *c)
47 while ((c->high >> 15) - (c->low >> 15) < 2) {
48 if ((c->low ^ c->high) & 0x10000) {
53 c->high = c->high << 8 & 0xFFFFFF | 0xFF;
54 c->value = c->value << 8 & 0xFFFFFF | bytestream2_get_byte(c->gbc.gB);
55 c->low = c->low << 8 & 0xFFFFFF;
61 /* L. Stuiver and A. Moffat: "Piecewise Integer Mapping for Arithmetic Coding."
62 * In Proc. 8th Data Compression Conference (DCC '98), pp. 3-12, Mar. 1998 */
64 static int arith2_get_scaled_value(int value, int n, int range)
66 int split = (n << 1) - range;
69 return split + (value - split >> 1);
74 static void arith2_rescale_interval(ArithCoder *c, int range,
75 int low, int high, int n)
77 int split = (n << 1) - range;
80 c->high = split + (high - split << 1);
84 c->high += c->low - 1;
87 c->low += split + (low - split << 1);
92 static int arith2_get_number(ArithCoder *c, int n)
94 int range = c->high - c->low + 1;
95 int scale = av_log2(range) - av_log2(n);
98 if (n << scale > range)
103 val = arith2_get_scaled_value(c->value - c->low, n, range) >> scale;
105 arith2_rescale_interval(c, range, val << scale, (val + 1) << scale, n);
112 static int arith2_get_prob(ArithCoder *c, int16_t *probs)
114 int range = c->high - c->low + 1, n = *probs;
115 int scale = av_log2(range) - av_log2(n);
118 if (n << scale > range)
123 val = arith2_get_scaled_value(c->value - c->low, n, range) >> scale;
124 while (probs[++i] > val) ;
126 arith2_rescale_interval(c, range,
127 probs[i] << scale, probs[i - 1] << scale, n);
132 ARITH_GET_MODEL_SYM(arith2)
134 static int arith2_get_consumed_bytes(ArithCoder *c)
136 int diff = (c->high >> 16) - (c->low >> 16);
137 int bp = bytestream2_tell(c->gbc.gB) - 3 << 3;
140 while (!(diff & 0x80)) {
145 return (bits + bp + 7 >> 3) + ((c->low >> 16) + 1 == c->high >> 16);
148 static void arith2_init(ArithCoder *c, GetByteContext *gB)
152 c->value = bytestream2_get_be24(gB);
154 c->get_model_sym = arith2_get_model_sym;
155 c->get_number = arith2_get_number;
158 static int decode_pal_v2(MSS12Context *ctx, const uint8_t *buf, int buf_size)
161 uint32_t *pal = ctx->pal + 256 - ctx->free_colours;
163 if (!ctx->free_colours)
167 if (ncol > ctx->free_colours || buf_size < 2 + ncol * 3)
168 return AVERROR_INVALIDDATA;
169 for (i = 0; i < ncol; i++)
170 *pal++ = AV_RB24(buf + 3 * i);
175 static int decode_555(GetByteContext *gB, uint16_t *dst, int stride,
176 int keyframe, int w, int h)
178 int last_symbol = 0, repeat = 0, prev_avail = 0;
181 int x, y, endx, endy, t;
183 #define READ_PAIR(a, b) \
184 a = bytestream2_get_byte(gB) << 4; \
185 t = bytestream2_get_byte(gB); \
187 b = (t & 0xF) << 8; \
188 b |= bytestream2_get_byte(gB); \
193 if (endx >= w || endy >= h || x > endx || y > endy)
194 return AVERROR_INVALIDDATA;
195 dst += x + stride * y;
206 int b = bytestream2_get_byte(gB);
208 last_symbol = b << 8 | bytestream2_get_byte(gB);
212 repeat = (repeat << 8) + bytestream2_get_byte(gB) + 1;
213 if (last_symbol == -2) {
214 int skip = FFMIN((unsigned)repeat, dst + w - p);
219 last_symbol = 127 - b;
221 if (last_symbol >= 0)
223 else if (last_symbol == -1 && prev_avail)
225 } while (++p < dst + w);
233 static int decode_rle(GetBitContext *gb, uint8_t *pal_dst, int pal_stride,
234 uint8_t *rgb_dst, int rgb_stride, uint32_t *pal,
235 int keyframe, int kf_slipt, int slice, int w, int h)
237 uint8_t bits[270] = { 0 };
241 int current_length = 0, read_codes = 0, next_code = 0, current_codes = 0;
242 int remaining_codes, surplus_codes, i;
244 const int alphabet_size = 270 - keyframe;
246 int last_symbol = 0, repeat = 0, prev_avail = 0;
249 int x, y, clipw, cliph;
251 x = get_bits(gb, 12);
252 y = get_bits(gb, 12);
253 clipw = get_bits(gb, 12) + 1;
254 cliph = get_bits(gb, 12) + 1;
256 if (x + clipw > w || y + cliph > h)
257 return AVERROR_INVALIDDATA;
258 pal_dst += pal_stride * y + x;
259 rgb_dst += rgb_stride * y + x * 3;
266 pal_dst += pal_stride * kf_slipt;
267 rgb_dst += rgb_stride * kf_slipt;
274 /* read explicit codes */
276 while (current_codes--) {
277 int symbol = get_bits(gb, 8);
278 if (symbol >= 204 - keyframe)
279 symbol += 14 - keyframe;
280 else if (symbol > 189)
281 symbol = get_bits1(gb) + (symbol << 1) - 190;
283 return AVERROR_INVALIDDATA;
284 bits[symbol] = current_length;
285 codes[symbol] = next_code++;
290 remaining_codes = (1 << current_length) - next_code;
291 current_codes = get_bits(gb, av_ceil_log2(remaining_codes + 1));
292 if (current_length > 22 || current_codes > remaining_codes)
293 return AVERROR_INVALIDDATA;
294 } while (current_codes != remaining_codes);
296 remaining_codes = alphabet_size - read_codes;
298 /* determine the minimum length to fit the rest of the alphabet */
299 while ((surplus_codes = (2 << current_length) -
300 (next_code << 1) - remaining_codes) < 0) {
305 /* add the rest of the symbols lexicographically */
306 for (i = 0; i < alphabet_size; i++)
308 if (surplus_codes-- == 0) {
312 bits[i] = current_length;
313 codes[i] = next_code++;
316 if (next_code != 1 << current_length)
317 return AVERROR_INVALIDDATA;
319 if (i = init_vlc(&vlc, 9, alphabet_size, bits, 1, 1, codes, 4, 4, 0))
324 uint8_t *pp = pal_dst;
325 uint8_t *rp = rgb_dst;
328 int b = get_vlc2(gb, vlc.table, 9, 3);
334 b = get_bits(gb, 4) + 10;
339 repeat = get_bits(gb, b);
341 repeat += (1 << b) - 1;
343 if (last_symbol == -2) {
344 int skip = FFMIN(repeat, pal_dst + w - pp);
350 last_symbol = 267 - b;
352 if (last_symbol >= 0) {
354 AV_WB24(rp, pal[last_symbol]);
355 } else if (last_symbol == -1 && prev_avail) {
356 *pp = *(pp - pal_stride);
357 memcpy(rp, rp - rgb_stride, 3);
360 } while (++pp < pal_dst + w);
361 pal_dst += pal_stride;
362 rgb_dst += rgb_stride;
370 static int decode_wmv9(AVCodecContext *avctx, const uint8_t *buf, int buf_size,
371 int x, int y, int w, int h, int wmv9_mask)
373 MSS2Context *ctx = avctx->priv_data;
374 MSS12Context *c = &ctx->c;
375 VC1Context *v = avctx->priv_data;
376 MpegEncContext *s = &v->s;
380 ff_mpeg_flush(avctx);
382 if ((ret = init_get_bits8(&s->gb, buf, buf_size)) < 0)
385 s->loop_filter = avctx->skip_loop_filter < AVDISCARD_ALL;
387 if (ff_vc1_parse_frame_header(v, &s->gb) < 0) {
388 av_log(v->s.avctx, AV_LOG_ERROR, "header error\n");
389 return AVERROR_INVALIDDATA;
392 if (s->pict_type != AV_PICTURE_TYPE_I) {
393 av_log(v->s.avctx, AV_LOG_ERROR, "expected I-frame\n");
394 return AVERROR_INVALIDDATA;
397 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
399 if ((ret = ff_MPV_frame_start(s, avctx)) < 0) {
400 av_log(v->s.avctx, AV_LOG_ERROR, "ff_MPV_frame_start error\n");
401 avctx->pix_fmt = AV_PIX_FMT_RGB24;
405 ff_mpeg_er_frame_start(s);
407 v->bits = buf_size * 8;
409 v->end_mb_x = (w + 15) >> 4;
410 s->end_mb_y = (h + 15) >> 4;
412 v->end_mb_x = v->end_mb_x + 1 >> 1;
414 s->end_mb_y = s->end_mb_y + 1 >> 1;
416 ff_vc1_decode_blocks(v);
418 ff_er_frame_end(&s->er);
422 f = s->current_picture.f;
424 if (v->respic == 3) {
425 ctx->dsp.upsample_plane(f->data[0], f->linesize[0], w, h);
426 ctx->dsp.upsample_plane(f->data[1], f->linesize[1], w+1 >> 1, h+1 >> 1);
427 ctx->dsp.upsample_plane(f->data[2], f->linesize[2], w+1 >> 1, h+1 >> 1);
428 } else if (v->respic)
429 avpriv_request_sample(v->s.avctx,
430 "Asymmetric WMV9 rectangle subsampling");
432 av_assert0(f->linesize[1] == f->linesize[2]);
435 ctx->dsp.mss2_blit_wmv9_masked(c->rgb_pic + y * c->rgb_stride + x * 3,
436 c->rgb_stride, wmv9_mask,
437 c->pal_pic + y * c->pal_stride + x,
439 f->data[0], f->linesize[0],
440 f->data[1], f->data[2], f->linesize[1],
443 ctx->dsp.mss2_blit_wmv9(c->rgb_pic + y * c->rgb_stride + x * 3,
445 f->data[0], f->linesize[0],
446 f->data[1], f->data[2], f->linesize[1],
449 avctx->pix_fmt = AV_PIX_FMT_RGB24;
454 typedef struct Rectangle {
455 int coded, x, y, w, h;
458 #define MAX_WMV9_RECTANGLES 20
459 #define ARITH2_PADDING 2
461 static int mss2_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
464 const uint8_t *buf = avpkt->data;
465 int buf_size = avpkt->size;
466 MSS2Context *ctx = avctx->priv_data;
467 MSS12Context *c = &ctx->c;
468 AVFrame *frame = data;
473 int keyframe, has_wmv9, has_mv, is_rle, is_555, ret;
475 Rectangle wmv9rects[MAX_WMV9_RECTANGLES], *r;
476 int used_rects = 0, i, implicit_rect = 0, av_uninit(wmv9_mask);
478 av_assert0(FF_INPUT_BUFFER_PADDING_SIZE >=
479 ARITH2_PADDING + (MIN_CACHE_BITS + 7) / 8);
481 if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
484 if (keyframe = get_bits1(&gb))
486 has_wmv9 = get_bits1(&gb);
487 has_mv = keyframe ? 0 : get_bits1(&gb);
488 is_rle = get_bits1(&gb);
489 is_555 = is_rle && get_bits1(&gb);
490 if (c->slice_split > 0)
491 ctx->split_position = c->slice_split;
492 else if (c->slice_split < 0) {
493 if (get_bits1(&gb)) {
494 if (get_bits1(&gb)) {
496 ctx->split_position = get_bits(&gb, 16);
498 ctx->split_position = get_bits(&gb, 12);
500 ctx->split_position = get_bits(&gb, 8) << 4;
503 ctx->split_position = avctx->height / 2;
506 ctx->split_position = avctx->height;
508 if (c->slice_split && (ctx->split_position < 1 - is_555 ||
509 ctx->split_position > avctx->height - 1))
510 return AVERROR_INVALIDDATA;
513 buf += get_bits_count(&gb) >> 3;
514 buf_size -= get_bits_count(&gb) >> 3;
517 return AVERROR_INVALIDDATA;
519 if (is_555 && (has_wmv9 || has_mv || c->slice_split && ctx->split_position))
520 return AVERROR_INVALIDDATA;
522 avctx->pix_fmt = is_555 ? AV_PIX_FMT_RGB555 : AV_PIX_FMT_RGB24;
523 if (ctx->last_pic->format != avctx->pix_fmt)
524 av_frame_unref(ctx->last_pic);
527 bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
528 arith2_init(&acoder, &gB);
530 implicit_rect = !arith2_get_bit(&acoder);
532 while (arith2_get_bit(&acoder)) {
533 if (used_rects == MAX_WMV9_RECTANGLES)
534 return AVERROR_INVALIDDATA;
535 r = &wmv9rects[used_rects];
537 r->x = arith2_get_number(&acoder, avctx->width);
539 r->x = arith2_get_number(&acoder, avctx->width -
540 wmv9rects[used_rects - 1].x) +
541 wmv9rects[used_rects - 1].x;
542 r->y = arith2_get_number(&acoder, avctx->height);
543 r->w = arith2_get_number(&acoder, avctx->width - r->x) + 1;
544 r->h = arith2_get_number(&acoder, avctx->height - r->y) + 1;
548 if (implicit_rect && used_rects) {
549 av_log(avctx, AV_LOG_ERROR, "implicit_rect && used_rects > 0\n");
550 return AVERROR_INVALIDDATA;
556 wmv9rects[0].w = avctx->width;
557 wmv9rects[0].h = avctx->height;
561 for (i = 0; i < used_rects; i++) {
562 if (!implicit_rect && arith2_get_bit(&acoder)) {
563 av_log(avctx, AV_LOG_ERROR, "Unexpected grandchildren\n");
564 return AVERROR_INVALIDDATA;
567 wmv9_mask = arith2_get_bit(&acoder) - 1;
569 wmv9_mask = arith2_get_number(&acoder, 256);
571 wmv9rects[i].coded = arith2_get_number(&acoder, 2);
574 buf += arith2_get_consumed_bytes(&acoder);
575 buf_size -= arith2_get_consumed_bytes(&acoder);
577 return AVERROR_INVALIDDATA;
581 if (keyframe && !is_555) {
582 if ((i = decode_pal_v2(c, buf, buf_size)) < 0)
583 return AVERROR_INVALIDDATA;
590 return AVERROR_INVALIDDATA;
591 c->mvX = AV_RB16(buf - 4) - avctx->width;
592 c->mvY = AV_RB16(buf - 2) - avctx->height;
595 if (c->mvX < 0 || c->mvY < 0) {
596 FFSWAP(uint8_t *, c->pal_pic, c->last_pal_pic);
598 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
601 if (ctx->last_pic->data[0]) {
602 av_assert0(frame->linesize[0] == ctx->last_pic->linesize[0]);
603 c->last_rgb_pic = ctx->last_pic->data[0] +
604 ctx->last_pic->linesize[0] * (avctx->height - 1);
606 av_log(avctx, AV_LOG_ERROR, "Missing keyframe\n");
607 return AVERROR_INVALIDDATA;
610 if ((ret = ff_reget_buffer(avctx, ctx->last_pic)) < 0)
612 if ((ret = av_frame_ref(frame, ctx->last_pic)) < 0)
615 c->last_rgb_pic = NULL;
617 c->rgb_pic = frame->data[0] +
618 frame->linesize[0] * (avctx->height - 1);
619 c->rgb_stride = -frame->linesize[0];
621 frame->key_frame = keyframe;
622 frame->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
625 bytestream2_init(&gB, buf, buf_size);
627 if (decode_555(&gB, (uint16_t *)c->rgb_pic, c->rgb_stride >> 1,
628 keyframe, avctx->width, avctx->height))
629 return AVERROR_INVALIDDATA;
631 buf_size -= bytestream2_tell(&gB);
635 ff_mss12_slicecontext_reset(&ctx->sc[0]);
637 ff_mss12_slicecontext_reset(&ctx->sc[1]);
640 if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
642 if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
643 c->rgb_pic, c->rgb_stride, c->pal, keyframe,
644 ctx->split_position, 0,
645 avctx->width, avctx->height))
650 if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
651 c->rgb_pic, c->rgb_stride, c->pal, keyframe,
652 ctx->split_position, 1,
653 avctx->width, avctx->height))
657 buf += get_bits_count(&gb) >> 3;
658 buf_size -= get_bits_count(&gb) >> 3;
659 } else if (!implicit_rect || wmv9_mask != -1) {
661 return AVERROR_INVALIDDATA;
662 bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
663 arith2_init(&acoder, &gB);
664 c->keyframe = keyframe;
665 if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[0], &acoder, 0, 0,
667 ctx->split_position))
668 return AVERROR_INVALIDDATA;
670 buf += arith2_get_consumed_bytes(&acoder);
671 buf_size -= arith2_get_consumed_bytes(&acoder);
672 if (c->slice_split) {
674 return AVERROR_INVALIDDATA;
675 bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
676 arith2_init(&acoder, &gB);
677 if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[1], &acoder, 0,
680 avctx->height - ctx->split_position))
681 return AVERROR_INVALIDDATA;
683 buf += arith2_get_consumed_bytes(&acoder);
684 buf_size -= arith2_get_consumed_bytes(&acoder);
687 memset(c->pal_pic, 0, c->pal_stride * avctx->height);
691 for (i = 0; i < used_rects; i++) {
692 int x = wmv9rects[i].x;
693 int y = wmv9rects[i].y;
694 int w = wmv9rects[i].w;
695 int h = wmv9rects[i].h;
696 if (wmv9rects[i].coded) {
697 int WMV9codedFrameSize;
698 if (buf_size < 4 || !(WMV9codedFrameSize = AV_RL24(buf)))
699 return AVERROR_INVALIDDATA;
700 if (ret = decode_wmv9(avctx, buf + 3, buf_size - 3,
701 x, y, w, h, wmv9_mask))
703 buf += WMV9codedFrameSize + 3;
704 buf_size -= WMV9codedFrameSize + 3;
706 uint8_t *dst = c->rgb_pic + y * c->rgb_stride + x * 3;
707 if (wmv9_mask != -1) {
708 ctx->dsp.mss2_gray_fill_masked(dst, c->rgb_stride,
710 c->pal_pic + y * c->pal_stride + x,
715 memset(dst, 0x80, w * 3);
716 dst += c->rgb_stride;
724 av_log(avctx, AV_LOG_WARNING, "buffer not fully consumed\n");
726 if (c->mvX < 0 || c->mvY < 0) {
727 av_frame_unref(ctx->last_pic);
728 ret = av_frame_ref(ctx->last_pic, frame);
738 static av_cold int wmv9_init(AVCodecContext *avctx)
740 VC1Context *v = avctx->priv_data;
745 if ((ret = ff_vc1_init_common(v)) < 0)
747 ff_vc1dsp_init(&v->vc1dsp);
749 v->profile = PROFILE_MAIN;
751 v->zz_8x4 = ff_wmv2_scantableA;
752 v->zz_4x8 = ff_wmv2_scantableB;
756 v->frmrtq_postproc = 7;
757 v->bitrtq_postproc = 31;
774 v->resync_marker = 0;
777 v->s.max_b_frames = avctx->max_b_frames = 0;
778 v->quantizer_mode = 0;
784 ff_vc1_init_transposed_scantables(v);
786 if ((ret = ff_msmpeg4_decode_init(avctx)) < 0 ||
787 (ret = ff_vc1_decode_init_alloc_tables(v)) < 0)
790 /* error concealment */
791 v->s.me.qpel_put = v->s.qdsp.put_qpel_pixels_tab;
792 v->s.me.qpel_avg = v->s.qdsp.avg_qpel_pixels_tab;
797 static av_cold int mss2_decode_end(AVCodecContext *avctx)
799 MSS2Context *const ctx = avctx->priv_data;
801 av_frame_free(&ctx->last_pic);
803 ff_mss12_decode_end(&ctx->c);
804 av_freep(&ctx->c.pal_pic);
805 av_freep(&ctx->c.last_pal_pic);
806 ff_vc1_decode_end(avctx);
811 static av_cold int mss2_decode_init(AVCodecContext *avctx)
813 MSS2Context * const ctx = avctx->priv_data;
814 MSS12Context *c = &ctx->c;
817 if (ret = ff_mss12_decode_init(c, 1, &ctx->sc[0], &ctx->sc[1]))
819 ctx->last_pic = av_frame_alloc();
820 c->pal_stride = c->mask_stride;
821 c->pal_pic = av_mallocz(c->pal_stride * avctx->height);
822 c->last_pal_pic = av_mallocz(c->pal_stride * avctx->height);
823 if (!c->pal_pic || !c->last_pal_pic || !ctx->last_pic) {
824 mss2_decode_end(avctx);
825 return AVERROR(ENOMEM);
827 if (ret = wmv9_init(avctx)) {
828 mss2_decode_end(avctx);
831 ff_mss2dsp_init(&ctx->dsp);
832 ff_qpeldsp_init(&ctx->qdsp);
834 avctx->pix_fmt = c->free_colours == 127 ? AV_PIX_FMT_RGB555
841 AVCodec ff_mss2_decoder = {
843 .long_name = NULL_IF_CONFIG_SMALL("MS Windows Media Video V9 Screen"),
844 .type = AVMEDIA_TYPE_VIDEO,
845 .id = AV_CODEC_ID_MSS2,
846 .priv_data_size = sizeof(MSS2Context),
847 .init = mss2_decode_init,
848 .close = mss2_decode_end,
849 .decode = mss2_decode_frame,
850 .capabilities = CODEC_CAP_DR1,