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"
34 typedef struct MSS2Context {
43 static void arith2_normalise(ArithCoder *c)
45 while ((c->high >> 15) - (c->low >> 15) < 2) {
46 if ((c->low ^ c->high) & 0x10000) {
51 c->high = c->high << 8 & 0xFFFFFF | 0xFF;
52 c->value = c->value << 8 & 0xFFFFFF | bytestream2_get_byte(c->gbc.gB);
53 c->low = c->low << 8 & 0xFFFFFF;
59 /* L. Stuiver and A. Moffat: "Piecewise Integer Mapping for Arithmetic Coding."
60 * In Proc. 8th Data Compression Conference (DCC '98), pp. 3-12, Mar. 1998 */
62 static int arith2_get_scaled_value(int value, int n, int range)
64 int split = (n << 1) - range;
67 return split + (value - split >> 1);
72 static void arith2_rescale_interval(ArithCoder *c, int range,
73 int low, int high, int n)
75 int split = (n << 1) - range;
78 c->high = split + (high - split << 1);
82 c->high += c->low - 1;
85 c->low += split + (low - split << 1);
90 static int arith2_get_number(ArithCoder *c, int n)
92 int range = c->high - c->low + 1;
93 int scale = av_log2(range) - av_log2(n);
96 if (n << scale > range)
101 val = arith2_get_scaled_value(c->value - c->low, n, range) >> scale;
103 arith2_rescale_interval(c, range, val << scale, (val + 1) << scale, n);
110 static int arith2_get_prob(ArithCoder *c, int16_t *probs)
112 int range = c->high - c->low + 1, n = *probs;
113 int scale = av_log2(range) - av_log2(n);
116 if (n << scale > range)
121 val = arith2_get_scaled_value(c->value - c->low, n, range) >> scale;
122 while (probs[++i] > val) ;
124 arith2_rescale_interval(c, range,
125 probs[i] << scale, probs[i - 1] << scale, n);
130 ARITH_GET_MODEL_SYM(2)
132 static int arith2_get_consumed_bytes(ArithCoder *c)
134 int diff = (c->high >> 16) - (c->low >> 16);
135 int bp = bytestream2_tell(c->gbc.gB) - 3 << 3;
138 while (!(diff & 0x80)) {
143 return (bits + bp + 7 >> 3) + ((c->low >> 16) + 1 == c->high >> 16);
146 static void arith2_init(ArithCoder *c, GetByteContext *gB)
150 c->value = bytestream2_get_be24(gB);
152 c->get_model_sym = arith2_get_model_sym;
153 c->get_number = arith2_get_number;
156 static int decode_pal_v2(MSS12Context *ctx, const uint8_t *buf, int buf_size)
159 uint32_t *pal = ctx->pal + 256 - ctx->free_colours;
161 if (!ctx->free_colours)
165 if (ncol > ctx->free_colours || buf_size < 2 + ncol * 3)
166 return AVERROR_INVALIDDATA;
167 for (i = 0; i < ncol; i++)
168 *pal++ = AV_RB24(buf + 3 * i);
173 static int decode_555(GetByteContext *gB, uint16_t *dst, int stride,
174 int keyframe, int w, int h)
176 int last_symbol = 0, repeat = 0, prev_avail = 0;
179 int x, y, endx, endy, t;
181 #define READ_PAIR(a, b) \
182 a = bytestream2_get_byte(gB) << 4; \
183 t = bytestream2_get_byte(gB); \
185 b = (t & 0xF) << 8; \
186 b |= bytestream2_get_byte(gB); \
191 if (endx >= w || endy >= h || x > endx || y > endy)
192 return AVERROR_INVALIDDATA;
193 dst += x + stride * y;
204 int b = bytestream2_get_byte(gB);
206 last_symbol = b << 8 | bytestream2_get_byte(gB);
210 repeat = (repeat << 8) + bytestream2_get_byte(gB) + 1;
211 if (last_symbol == -2) {
212 int skip = FFMIN((unsigned)repeat, dst + w - p);
217 last_symbol = 127 - b;
219 if (last_symbol >= 0)
221 else if (last_symbol == -1 && prev_avail)
223 } while (++p < dst + w);
231 static int decode_rle(GetBitContext *gb, uint8_t *pal_dst, int pal_stride,
232 uint8_t *rgb_dst, int rgb_stride, uint32_t *pal,
233 int keyframe, int kf_slipt, int slice, int w, int h)
235 uint8_t bits[270] = { 0 };
239 int current_length = 0, read_codes = 0, next_code = 0, current_codes = 0;
240 int remaining_codes, surplus_codes, i;
242 const int alphabet_size = 270 - keyframe;
244 int last_symbol = 0, repeat = 0, prev_avail = 0;
247 int x, y, clipw, cliph;
249 x = get_bits(gb, 12);
250 y = get_bits(gb, 12);
251 clipw = get_bits(gb, 12) + 1;
252 cliph = get_bits(gb, 12) + 1;
254 if (x + clipw > w || y + cliph > h)
255 return AVERROR_INVALIDDATA;
256 pal_dst += pal_stride * y + x;
257 rgb_dst += rgb_stride * y + x * 3;
264 pal_dst += pal_stride * kf_slipt;
265 rgb_dst += rgb_stride * kf_slipt;
272 /* read explicit codes */
274 while (current_codes--) {
275 int symbol = get_bits(gb, 8);
276 if (symbol >= 204 - keyframe)
277 symbol += 14 - keyframe;
278 else if (symbol > 189)
279 symbol = get_bits1(gb) + (symbol << 1) - 190;
281 return AVERROR_INVALIDDATA;
282 bits[symbol] = current_length;
283 codes[symbol] = next_code++;
288 remaining_codes = (1 << current_length) - next_code;
289 current_codes = get_bits(gb, av_ceil_log2(remaining_codes + 1));
290 if (current_length > 22 || current_codes > remaining_codes)
291 return AVERROR_INVALIDDATA;
292 } while (current_codes != remaining_codes);
294 remaining_codes = alphabet_size - read_codes;
296 /* determine the minimum length to fit the rest of the alphabet */
297 while ((surplus_codes = (2 << current_length) -
298 (next_code << 1) - remaining_codes) < 0) {
303 /* add the rest of the symbols lexicographically */
304 for (i = 0; i < alphabet_size; i++)
306 if (surplus_codes-- == 0) {
310 bits[i] = current_length;
311 codes[i] = next_code++;
314 if (next_code != 1 << current_length)
315 return AVERROR_INVALIDDATA;
317 if (i = init_vlc(&vlc, 9, alphabet_size, bits, 1, 1, codes, 4, 4, 0))
322 uint8_t *pp = pal_dst;
323 uint8_t *rp = rgb_dst;
326 int b = get_vlc2(gb, vlc.table, 9, 3);
332 b = get_bits(gb, 4) + 10;
337 repeat = get_bits(gb, b);
339 repeat += (1 << b) - 1;
341 if (last_symbol == -2) {
342 int skip = FFMIN(repeat, pal_dst + w - pp);
348 last_symbol = 267 - b;
350 if (last_symbol >= 0) {
352 AV_WB24(rp, pal[last_symbol]);
353 } else if (last_symbol == -1 && prev_avail) {
354 *pp = *(pp - pal_stride);
355 memcpy(rp, rp - rgb_stride, 3);
358 } while (++pp < pal_dst + w);
359 pal_dst += pal_stride;
360 rgb_dst += rgb_stride;
368 static int decode_wmv9(AVCodecContext *avctx, const uint8_t *buf, int buf_size,
369 int x, int y, int w, int h, int wmv9_mask)
371 MSS2Context *ctx = avctx->priv_data;
372 MSS12Context *c = &ctx->c;
373 VC1Context *v = avctx->priv_data;
374 MpegEncContext *s = &v->s;
378 ff_mpeg_flush(avctx);
380 if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
381 int i = ff_find_unused_picture(s, 0);
384 s->current_picture_ptr = &s->picture[i];
387 if ((ret = init_get_bits8(&s->gb, buf, buf_size)) < 0)
390 s->loop_filter = avctx->skip_loop_filter < AVDISCARD_ALL;
392 if (ff_vc1_parse_frame_header(v, &s->gb) < 0) {
393 av_log(v->s.avctx, AV_LOG_ERROR, "header error\n");
394 return AVERROR_INVALIDDATA;
397 if (s->pict_type != AV_PICTURE_TYPE_I) {
398 av_log(v->s.avctx, AV_LOG_ERROR, "expected I-frame\n");
399 return AVERROR_INVALIDDATA;
402 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
404 if ((ret = ff_MPV_frame_start(s, avctx)) < 0) {
405 av_log(v->s.avctx, AV_LOG_ERROR, "ff_MPV_frame_start error\n");
406 avctx->pix_fmt = AV_PIX_FMT_RGB24;
410 ff_mpeg_er_frame_start(s);
412 v->bits = buf_size * 8;
414 v->end_mb_x = (w + 15) >> 4;
415 s->end_mb_y = (h + 15) >> 4;
417 v->end_mb_x = v->end_mb_x + 1 >> 1;
419 s->end_mb_y = s->end_mb_y + 1 >> 1;
421 ff_vc1_decode_blocks(v);
423 ff_er_frame_end(&s->er);
427 f = &s->current_picture.f;
429 if (v->respic == 3) {
430 ctx->dsp.upsample_plane(f->data[0], f->linesize[0], w, h);
431 ctx->dsp.upsample_plane(f->data[1], f->linesize[1], w >> 1, h >> 1);
432 ctx->dsp.upsample_plane(f->data[2], f->linesize[2], w >> 1, h >> 1);
433 } else if (v->respic)
434 avpriv_request_sample(v->s.avctx,
435 "Asymmetric WMV9 rectangle subsampling");
437 av_assert0(f->linesize[1] == f->linesize[2]);
440 ctx->dsp.mss2_blit_wmv9_masked(c->rgb_pic + y * c->rgb_stride + x * 3,
441 c->rgb_stride, wmv9_mask,
442 c->pal_pic + y * c->pal_stride + x,
444 f->data[0], f->linesize[0],
445 f->data[1], f->data[2], f->linesize[1],
448 ctx->dsp.mss2_blit_wmv9(c->rgb_pic + y * c->rgb_stride + x * 3,
450 f->data[0], f->linesize[0],
451 f->data[1], f->data[2], f->linesize[1],
454 avctx->pix_fmt = AV_PIX_FMT_RGB24;
459 typedef struct Rectangle {
460 int coded, x, y, w, h;
463 #define MAX_WMV9_RECTANGLES 20
464 #define ARITH2_PADDING 2
466 static int mss2_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
469 const uint8_t *buf = avpkt->data;
470 int buf_size = avpkt->size;
471 MSS2Context *ctx = avctx->priv_data;
472 MSS12Context *c = &ctx->c;
473 AVFrame *frame = data;
478 int keyframe, has_wmv9, has_mv, is_rle, is_555, ret;
480 Rectangle wmv9rects[MAX_WMV9_RECTANGLES], *r;
481 int used_rects = 0, i, implicit_rect = 0, av_uninit(wmv9_mask);
483 av_assert0(FF_INPUT_BUFFER_PADDING_SIZE >=
484 ARITH2_PADDING + (MIN_CACHE_BITS + 7) / 8);
486 if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
489 if (keyframe = get_bits1(&gb))
491 has_wmv9 = get_bits1(&gb);
492 has_mv = keyframe ? 0 : get_bits1(&gb);
493 is_rle = get_bits1(&gb);
494 is_555 = is_rle && get_bits1(&gb);
495 if (c->slice_split > 0)
496 ctx->split_position = c->slice_split;
497 else if (c->slice_split < 0) {
498 if (get_bits1(&gb)) {
499 if (get_bits1(&gb)) {
501 ctx->split_position = get_bits(&gb, 16);
503 ctx->split_position = get_bits(&gb, 12);
505 ctx->split_position = get_bits(&gb, 8) << 4;
508 ctx->split_position = avctx->height / 2;
511 ctx->split_position = avctx->height;
513 if (c->slice_split && (ctx->split_position < 1 - is_555 ||
514 ctx->split_position > avctx->height - 1))
515 return AVERROR_INVALIDDATA;
518 buf += get_bits_count(&gb) >> 3;
519 buf_size -= get_bits_count(&gb) >> 3;
522 return AVERROR_INVALIDDATA;
524 if (is_555 && (has_wmv9 || has_mv || c->slice_split && ctx->split_position))
525 return AVERROR_INVALIDDATA;
527 avctx->pix_fmt = is_555 ? AV_PIX_FMT_RGB555 : AV_PIX_FMT_RGB24;
528 if (ctx->last_pic->format != avctx->pix_fmt)
529 av_frame_unref(ctx->last_pic);
532 bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
533 arith2_init(&acoder, &gB);
535 implicit_rect = !arith2_get_bit(&acoder);
537 while (arith2_get_bit(&acoder)) {
538 if (used_rects == MAX_WMV9_RECTANGLES)
539 return AVERROR_INVALIDDATA;
540 r = &wmv9rects[used_rects];
542 r->x = arith2_get_number(&acoder, avctx->width);
544 r->x = arith2_get_number(&acoder, avctx->width -
545 wmv9rects[used_rects - 1].x) +
546 wmv9rects[used_rects - 1].x;
547 r->y = arith2_get_number(&acoder, avctx->height);
548 r->w = arith2_get_number(&acoder, avctx->width - r->x) + 1;
549 r->h = arith2_get_number(&acoder, avctx->height - r->y) + 1;
553 if (implicit_rect && used_rects) {
554 av_log(avctx, AV_LOG_ERROR, "implicit_rect && used_rects > 0\n");
555 return AVERROR_INVALIDDATA;
561 wmv9rects[0].w = avctx->width;
562 wmv9rects[0].h = avctx->height;
566 for (i = 0; i < used_rects; i++) {
567 if (!implicit_rect && arith2_get_bit(&acoder)) {
568 av_log(avctx, AV_LOG_ERROR, "Unexpected grandchildren\n");
569 return AVERROR_INVALIDDATA;
572 wmv9_mask = arith2_get_bit(&acoder) - 1;
574 wmv9_mask = arith2_get_number(&acoder, 256);
576 wmv9rects[i].coded = arith2_get_number(&acoder, 2);
579 buf += arith2_get_consumed_bytes(&acoder);
580 buf_size -= arith2_get_consumed_bytes(&acoder);
582 return AVERROR_INVALIDDATA;
586 if (keyframe && !is_555) {
587 if ((i = decode_pal_v2(c, buf, buf_size)) < 0)
588 return AVERROR_INVALIDDATA;
595 return AVERROR_INVALIDDATA;
596 c->mvX = AV_RB16(buf - 4) - avctx->width;
597 c->mvY = AV_RB16(buf - 2) - avctx->height;
600 if (c->mvX < 0 || c->mvY < 0) {
601 FFSWAP(uint8_t *, c->pal_pic, c->last_pal_pic);
603 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
606 if (ctx->last_pic->data[0]) {
607 av_assert0(frame->linesize[0] == ctx->last_pic->linesize[0]);
608 c->last_rgb_pic = ctx->last_pic->data[0] +
609 ctx->last_pic->linesize[0] * (avctx->height - 1);
611 av_log(avctx, AV_LOG_ERROR, "Missing keyframe\n");
612 return AVERROR_INVALIDDATA;
615 if ((ret = ff_reget_buffer(avctx, ctx->last_pic)) < 0)
617 if ((ret = av_frame_ref(frame, ctx->last_pic)) < 0)
620 c->last_rgb_pic = NULL;
622 c->rgb_pic = frame->data[0] +
623 frame->linesize[0] * (avctx->height - 1);
624 c->rgb_stride = -frame->linesize[0];
626 frame->key_frame = keyframe;
627 frame->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
630 bytestream2_init(&gB, buf, buf_size);
632 if (decode_555(&gB, (uint16_t *)c->rgb_pic, c->rgb_stride >> 1,
633 keyframe, avctx->width, avctx->height))
634 return AVERROR_INVALIDDATA;
636 buf_size -= bytestream2_tell(&gB);
640 ff_mss12_slicecontext_reset(&ctx->sc[0]);
642 ff_mss12_slicecontext_reset(&ctx->sc[1]);
645 if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
647 if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
648 c->rgb_pic, c->rgb_stride, c->pal, keyframe,
649 ctx->split_position, 0,
650 avctx->width, avctx->height))
655 if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
656 c->rgb_pic, c->rgb_stride, c->pal, keyframe,
657 ctx->split_position, 1,
658 avctx->width, avctx->height))
662 buf += get_bits_count(&gb) >> 3;
663 buf_size -= get_bits_count(&gb) >> 3;
664 } else if (!implicit_rect || wmv9_mask != -1) {
666 return AVERROR_INVALIDDATA;
667 bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
668 arith2_init(&acoder, &gB);
669 c->keyframe = keyframe;
670 if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[0], &acoder, 0, 0,
672 ctx->split_position))
673 return AVERROR_INVALIDDATA;
675 buf += arith2_get_consumed_bytes(&acoder);
676 buf_size -= arith2_get_consumed_bytes(&acoder);
677 if (c->slice_split) {
679 return AVERROR_INVALIDDATA;
680 bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
681 arith2_init(&acoder, &gB);
682 if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[1], &acoder, 0,
685 avctx->height - ctx->split_position))
686 return AVERROR_INVALIDDATA;
688 buf += arith2_get_consumed_bytes(&acoder);
689 buf_size -= arith2_get_consumed_bytes(&acoder);
692 memset(c->pal_pic, 0, c->pal_stride * avctx->height);
696 for (i = 0; i < used_rects; i++) {
697 int x = wmv9rects[i].x;
698 int y = wmv9rects[i].y;
699 int w = wmv9rects[i].w;
700 int h = wmv9rects[i].h;
701 if (wmv9rects[i].coded) {
702 int WMV9codedFrameSize;
703 if (buf_size < 4 || !(WMV9codedFrameSize = AV_RL24(buf)))
704 return AVERROR_INVALIDDATA;
705 if (ret = decode_wmv9(avctx, buf + 3, buf_size - 3,
706 x, y, w, h, wmv9_mask))
708 buf += WMV9codedFrameSize + 3;
709 buf_size -= WMV9codedFrameSize + 3;
711 uint8_t *dst = c->rgb_pic + y * c->rgb_stride + x * 3;
712 if (wmv9_mask != -1) {
713 ctx->dsp.mss2_gray_fill_masked(dst, c->rgb_stride,
715 c->pal_pic + y * c->pal_stride + x,
720 memset(dst, 0x80, w * 3);
721 dst += c->rgb_stride;
729 av_log(avctx, AV_LOG_WARNING, "buffer not fully consumed\n");
731 if (c->mvX < 0 || c->mvY < 0) {
732 av_frame_unref(ctx->last_pic);
733 ret = av_frame_ref(ctx->last_pic, frame);
743 static av_cold int wmv9_init(AVCodecContext *avctx)
745 VC1Context *v = avctx->priv_data;
749 avctx->flags |= CODEC_FLAG_EMU_EDGE;
750 v->s.flags |= CODEC_FLAG_EMU_EDGE;
752 if ((ret = ff_vc1_init_common(v)) < 0)
754 ff_vc1dsp_init(&v->vc1dsp);
756 v->profile = PROFILE_MAIN;
758 v->zz_8x4 = ff_wmv2_scantableA;
759 v->zz_4x8 = ff_wmv2_scantableB;
763 v->frmrtq_postproc = 7;
764 v->bitrtq_postproc = 31;
781 v->s.resync_marker = 0;
784 v->s.max_b_frames = avctx->max_b_frames = 0;
785 v->quantizer_mode = 0;
791 ff_vc1_init_transposed_scantables(v);
793 if ((ret = ff_msmpeg4_decode_init(avctx)) < 0 ||
794 (ret = ff_vc1_decode_init_alloc_tables(v)) < 0)
797 /* error concealment */
798 v->s.me.qpel_put = v->s.dsp.put_qpel_pixels_tab;
799 v->s.me.qpel_avg = v->s.dsp.avg_qpel_pixels_tab;
804 static av_cold int mss2_decode_end(AVCodecContext *avctx)
806 MSS2Context *const ctx = avctx->priv_data;
808 av_frame_free(&ctx->last_pic);
810 ff_mss12_decode_end(&ctx->c);
811 av_freep(&ctx->c.pal_pic);
812 av_freep(&ctx->c.last_pal_pic);
813 ff_vc1_decode_end(avctx);
818 static av_cold int mss2_decode_init(AVCodecContext *avctx)
820 MSS2Context * const ctx = avctx->priv_data;
821 MSS12Context *c = &ctx->c;
824 if (ret = ff_mss12_decode_init(c, 1, &ctx->sc[0], &ctx->sc[1]))
826 ctx->last_pic = av_frame_alloc();
827 c->pal_stride = c->mask_stride;
828 c->pal_pic = av_mallocz(c->pal_stride * avctx->height);
829 c->last_pal_pic = av_mallocz(c->pal_stride * avctx->height);
830 if (!c->pal_pic || !c->last_pal_pic || !ctx->last_pic) {
831 mss2_decode_end(avctx);
832 return AVERROR(ENOMEM);
834 if (ret = wmv9_init(avctx)) {
835 mss2_decode_end(avctx);
838 ff_mss2dsp_init(&ctx->dsp);
840 avctx->pix_fmt = c->free_colours == 127 ? AV_PIX_FMT_RGB555
847 AVCodec ff_mss2_decoder = {
849 .long_name = NULL_IF_CONFIG_SMALL("MS Windows Media Video V9 Screen"),
850 .type = AVMEDIA_TYPE_VIDEO,
851 .id = AV_CODEC_ID_MSS2,
852 .priv_data_size = sizeof(MSS2Context),
853 .init = mss2_decode_init,
854 .close = mss2_decode_end,
855 .decode = mss2_decode_frame,
856 .capabilities = CODEC_CAP_DR1,