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"
30 #include "msmpeg4data.h"
36 typedef struct MSS2Context {
46 static void arith2_normalise(ArithCoder *c)
48 while ((c->high >> 15) - (c->low >> 15) < 2) {
49 if ((c->low ^ c->high) & 0x10000) {
54 c->high = c->high << 8 & 0xFFFFFF | 0xFF;
55 c->value = c->value << 8 & 0xFFFFFF | bytestream2_get_byte(c->gbc.gB);
56 c->low = c->low << 8 & 0xFFFFFF;
62 /* L. Stuiver and A. Moffat: "Piecewise Integer Mapping for Arithmetic Coding."
63 * In Proc. 8th Data Compression Conference (DCC '98), pp. 3-12, Mar. 1998 */
65 static int arith2_get_scaled_value(int value, int n, int range)
67 int split = (n << 1) - range;
70 return split + (value - split >> 1);
75 static void arith2_rescale_interval(ArithCoder *c, int range,
76 int low, int high, int n)
78 int split = (n << 1) - range;
81 c->high = split + (high - split << 1);
85 c->high += c->low - 1;
88 c->low += split + (low - split << 1);
93 static int arith2_get_number(ArithCoder *c, int n)
95 int range = c->high - c->low + 1;
96 int scale = av_log2(range) - av_log2(n);
99 if (n << scale > range)
104 val = arith2_get_scaled_value(c->value - c->low, n, range) >> scale;
106 arith2_rescale_interval(c, range, val << scale, (val + 1) << scale, n);
113 static int arith2_get_prob(ArithCoder *c, int16_t *probs)
115 int range = c->high - c->low + 1, n = *probs;
116 int scale = av_log2(range) - av_log2(n);
119 if (n << scale > range)
124 val = arith2_get_scaled_value(c->value - c->low, n, range) >> scale;
125 while (probs[++i] > val) ;
127 arith2_rescale_interval(c, range,
128 probs[i] << scale, probs[i - 1] << scale, n);
133 ARITH_GET_MODEL_SYM(arith2)
135 static int arith2_get_consumed_bytes(ArithCoder *c)
137 int diff = (c->high >> 16) - (c->low >> 16);
138 int bp = bytestream2_tell(c->gbc.gB) - 3 << 3;
141 while (!(diff & 0x80)) {
146 return (bits + bp + 7 >> 3) + ((c->low >> 16) + 1 == c->high >> 16);
149 static void arith2_init(ArithCoder *c, GetByteContext *gB)
153 c->value = bytestream2_get_be24(gB);
155 c->get_model_sym = arith2_get_model_sym;
156 c->get_number = arith2_get_number;
159 static int decode_pal_v2(MSS12Context *ctx, const uint8_t *buf, int buf_size)
162 uint32_t *pal = ctx->pal + 256 - ctx->free_colours;
164 if (!ctx->free_colours)
168 if (ncol > ctx->free_colours || buf_size < 2 + ncol * 3)
169 return AVERROR_INVALIDDATA;
170 for (i = 0; i < ncol; i++)
171 *pal++ = AV_RB24(buf + 3 * i);
176 static int decode_555(GetByteContext *gB, uint16_t *dst, int stride,
177 int keyframe, int w, int h)
179 int last_symbol = 0, repeat = 0, prev_avail = 0;
182 int x, y, endx, endy, t;
184 #define READ_PAIR(a, b) \
185 a = bytestream2_get_byte(gB) << 4; \
186 t = bytestream2_get_byte(gB); \
188 b = (t & 0xF) << 8; \
189 b |= bytestream2_get_byte(gB); \
194 if (endx >= w || endy >= h || x > endx || y > endy)
195 return AVERROR_INVALIDDATA;
196 dst += x + stride * y;
207 int b = bytestream2_get_byte(gB);
209 last_symbol = b << 8 | bytestream2_get_byte(gB);
213 repeat = (repeat << 8) + bytestream2_get_byte(gB) + 1;
214 if (last_symbol == -2) {
215 int skip = FFMIN((unsigned)repeat, dst + w - p);
220 last_symbol = 127 - b;
222 if (last_symbol >= 0)
224 else if (last_symbol == -1 && prev_avail)
226 } while (++p < dst + w);
234 static int decode_rle(GetBitContext *gb, uint8_t *pal_dst, int pal_stride,
235 uint8_t *rgb_dst, int rgb_stride, uint32_t *pal,
236 int keyframe, int kf_slipt, int slice, int w, int h)
238 uint8_t bits[270] = { 0 };
242 int current_length = 0, read_codes = 0, next_code = 0, current_codes = 0;
243 int remaining_codes, surplus_codes, i;
245 const int alphabet_size = 270 - keyframe;
247 int last_symbol = 0, repeat = 0, prev_avail = 0;
250 int x, y, clipw, cliph;
252 x = get_bits(gb, 12);
253 y = get_bits(gb, 12);
254 clipw = get_bits(gb, 12) + 1;
255 cliph = get_bits(gb, 12) + 1;
257 if (x + clipw > w || y + cliph > h)
258 return AVERROR_INVALIDDATA;
259 pal_dst += pal_stride * y + x;
260 rgb_dst += rgb_stride * y + x * 3;
267 pal_dst += pal_stride * kf_slipt;
268 rgb_dst += rgb_stride * kf_slipt;
275 /* read explicit codes */
277 while (current_codes--) {
278 int symbol = get_bits(gb, 8);
279 if (symbol >= 204 - keyframe)
280 symbol += 14 - keyframe;
281 else if (symbol > 189)
282 symbol = get_bits1(gb) + (symbol << 1) - 190;
284 return AVERROR_INVALIDDATA;
285 bits[symbol] = current_length;
286 codes[symbol] = next_code++;
291 remaining_codes = (1 << current_length) - next_code;
292 current_codes = get_bits(gb, av_ceil_log2(remaining_codes + 1));
293 if (current_length > 22 || current_codes > remaining_codes)
294 return AVERROR_INVALIDDATA;
295 } while (current_codes != remaining_codes);
297 remaining_codes = alphabet_size - read_codes;
299 /* determine the minimum length to fit the rest of the alphabet */
300 while ((surplus_codes = (2 << current_length) -
301 (next_code << 1) - remaining_codes) < 0) {
306 /* add the rest of the symbols lexicographically */
307 for (i = 0; i < alphabet_size; i++)
309 if (surplus_codes-- == 0) {
313 bits[i] = current_length;
314 codes[i] = next_code++;
317 if (next_code != 1 << current_length)
318 return AVERROR_INVALIDDATA;
320 if (i = init_vlc(&vlc, 9, alphabet_size, bits, 1, 1, codes, 4, 4, 0))
325 uint8_t *pp = pal_dst;
326 uint8_t *rp = rgb_dst;
329 int b = get_vlc2(gb, vlc.table, 9, 3);
335 b = get_bits(gb, 4) + 10;
340 repeat = get_bits(gb, b);
342 repeat += (1 << b) - 1;
344 if (last_symbol == -2) {
345 int skip = FFMIN(repeat, pal_dst + w - pp);
351 last_symbol = 267 - b;
353 if (last_symbol >= 0) {
355 AV_WB24(rp, pal[last_symbol]);
356 } else if (last_symbol == -1 && prev_avail) {
357 *pp = *(pp - pal_stride);
358 memcpy(rp, rp - rgb_stride, 3);
361 } while (++pp < pal_dst + w);
362 pal_dst += pal_stride;
363 rgb_dst += rgb_stride;
371 static int decode_wmv9(AVCodecContext *avctx, const uint8_t *buf, int buf_size,
372 int x, int y, int w, int h, int wmv9_mask)
374 MSS2Context *ctx = avctx->priv_data;
375 MSS12Context *c = &ctx->c;
376 VC1Context *v = avctx->priv_data;
377 MpegEncContext *s = &v->s;
381 ff_mpeg_flush(avctx);
383 if ((ret = init_get_bits8(&s->gb, buf, buf_size)) < 0)
386 s->loop_filter = avctx->skip_loop_filter < AVDISCARD_ALL;
388 if (ff_vc1_parse_frame_header(v, &s->gb) < 0) {
389 av_log(v->s.avctx, AV_LOG_ERROR, "header error\n");
390 return AVERROR_INVALIDDATA;
393 if (s->pict_type != AV_PICTURE_TYPE_I) {
394 av_log(v->s.avctx, AV_LOG_ERROR, "expected I-frame\n");
395 return AVERROR_INVALIDDATA;
398 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
400 if ((ret = ff_mpv_frame_start(s, avctx)) < 0) {
401 av_log(v->s.avctx, AV_LOG_ERROR, "ff_mpv_frame_start error\n");
402 avctx->pix_fmt = AV_PIX_FMT_RGB24;
406 ff_mpeg_er_frame_start(s);
408 v->bits = buf_size * 8;
410 v->end_mb_x = (w + 15) >> 4;
411 s->end_mb_y = (h + 15) >> 4;
413 v->end_mb_x = v->end_mb_x + 1 >> 1;
415 s->end_mb_y = s->end_mb_y + 1 >> 1;
417 ff_vc1_decode_blocks(v);
419 ff_er_frame_end(&s->er);
423 f = s->current_picture.f;
425 if (v->respic == 3) {
426 ctx->dsp.upsample_plane(f->data[0], f->linesize[0], w, h);
427 ctx->dsp.upsample_plane(f->data[1], f->linesize[1], w+1 >> 1, h+1 >> 1);
428 ctx->dsp.upsample_plane(f->data[2], f->linesize[2], w+1 >> 1, h+1 >> 1);
429 } else if (v->respic)
430 avpriv_request_sample(v->s.avctx,
431 "Asymmetric WMV9 rectangle subsampling");
433 av_assert0(f->linesize[1] == f->linesize[2]);
436 ctx->dsp.mss2_blit_wmv9_masked(c->rgb_pic + y * c->rgb_stride + x * 3,
437 c->rgb_stride, wmv9_mask,
438 c->pal_pic + y * c->pal_stride + x,
440 f->data[0], f->linesize[0],
441 f->data[1], f->data[2], f->linesize[1],
444 ctx->dsp.mss2_blit_wmv9(c->rgb_pic + y * c->rgb_stride + x * 3,
446 f->data[0], f->linesize[0],
447 f->data[1], f->data[2], f->linesize[1],
450 avctx->pix_fmt = AV_PIX_FMT_RGB24;
455 typedef struct Rectangle {
456 int coded, x, y, w, h;
459 #define MAX_WMV9_RECTANGLES 20
460 #define ARITH2_PADDING 2
462 static int mss2_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
465 const uint8_t *buf = avpkt->data;
466 int buf_size = avpkt->size;
467 MSS2Context *ctx = avctx->priv_data;
468 MSS12Context *c = &ctx->c;
469 AVFrame *frame = data;
474 int keyframe, has_wmv9, has_mv, is_rle, is_555, ret;
476 Rectangle wmv9rects[MAX_WMV9_RECTANGLES], *r;
477 int used_rects = 0, i, implicit_rect = 0, av_uninit(wmv9_mask);
479 av_assert0(FF_INPUT_BUFFER_PADDING_SIZE >=
480 ARITH2_PADDING + (MIN_CACHE_BITS + 7) / 8);
482 if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
485 if (keyframe = get_bits1(&gb))
487 has_wmv9 = get_bits1(&gb);
488 has_mv = keyframe ? 0 : get_bits1(&gb);
489 is_rle = get_bits1(&gb);
490 is_555 = is_rle && get_bits1(&gb);
491 if (c->slice_split > 0)
492 ctx->split_position = c->slice_split;
493 else if (c->slice_split < 0) {
494 if (get_bits1(&gb)) {
495 if (get_bits1(&gb)) {
497 ctx->split_position = get_bits(&gb, 16);
499 ctx->split_position = get_bits(&gb, 12);
501 ctx->split_position = get_bits(&gb, 8) << 4;
504 ctx->split_position = avctx->height / 2;
507 ctx->split_position = avctx->height;
509 if (c->slice_split && (ctx->split_position < 1 - is_555 ||
510 ctx->split_position > avctx->height - 1))
511 return AVERROR_INVALIDDATA;
514 buf += get_bits_count(&gb) >> 3;
515 buf_size -= get_bits_count(&gb) >> 3;
518 return AVERROR_INVALIDDATA;
520 if (is_555 && (has_wmv9 || has_mv || c->slice_split && ctx->split_position))
521 return AVERROR_INVALIDDATA;
523 avctx->pix_fmt = is_555 ? AV_PIX_FMT_RGB555 : AV_PIX_FMT_RGB24;
524 if (ctx->last_pic->format != avctx->pix_fmt)
525 av_frame_unref(ctx->last_pic);
528 bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
529 arith2_init(&acoder, &gB);
531 implicit_rect = !arith2_get_bit(&acoder);
533 while (arith2_get_bit(&acoder)) {
534 if (used_rects == MAX_WMV9_RECTANGLES)
535 return AVERROR_INVALIDDATA;
536 r = &wmv9rects[used_rects];
538 r->x = arith2_get_number(&acoder, avctx->width);
540 r->x = arith2_get_number(&acoder, avctx->width -
541 wmv9rects[used_rects - 1].x) +
542 wmv9rects[used_rects - 1].x;
543 r->y = arith2_get_number(&acoder, avctx->height);
544 r->w = arith2_get_number(&acoder, avctx->width - r->x) + 1;
545 r->h = arith2_get_number(&acoder, avctx->height - r->y) + 1;
549 if (implicit_rect && used_rects) {
550 av_log(avctx, AV_LOG_ERROR, "implicit_rect && used_rects > 0\n");
551 return AVERROR_INVALIDDATA;
557 wmv9rects[0].w = avctx->width;
558 wmv9rects[0].h = avctx->height;
562 for (i = 0; i < used_rects; i++) {
563 if (!implicit_rect && arith2_get_bit(&acoder)) {
564 av_log(avctx, AV_LOG_ERROR, "Unexpected grandchildren\n");
565 return AVERROR_INVALIDDATA;
568 wmv9_mask = arith2_get_bit(&acoder) - 1;
570 wmv9_mask = arith2_get_number(&acoder, 256);
572 wmv9rects[i].coded = arith2_get_number(&acoder, 2);
575 buf += arith2_get_consumed_bytes(&acoder);
576 buf_size -= arith2_get_consumed_bytes(&acoder);
578 return AVERROR_INVALIDDATA;
582 if (keyframe && !is_555) {
583 if ((i = decode_pal_v2(c, buf, buf_size)) < 0)
584 return AVERROR_INVALIDDATA;
591 return AVERROR_INVALIDDATA;
592 c->mvX = AV_RB16(buf - 4) - avctx->width;
593 c->mvY = AV_RB16(buf - 2) - avctx->height;
596 if (c->mvX < 0 || c->mvY < 0) {
597 FFSWAP(uint8_t *, c->pal_pic, c->last_pal_pic);
599 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
602 if (ctx->last_pic->data[0]) {
603 av_assert0(frame->linesize[0] == ctx->last_pic->linesize[0]);
604 c->last_rgb_pic = ctx->last_pic->data[0] +
605 ctx->last_pic->linesize[0] * (avctx->height - 1);
607 av_log(avctx, AV_LOG_ERROR, "Missing keyframe\n");
608 return AVERROR_INVALIDDATA;
611 if ((ret = ff_reget_buffer(avctx, ctx->last_pic)) < 0)
613 if ((ret = av_frame_ref(frame, ctx->last_pic)) < 0)
616 c->last_rgb_pic = NULL;
618 c->rgb_pic = frame->data[0] +
619 frame->linesize[0] * (avctx->height - 1);
620 c->rgb_stride = -frame->linesize[0];
622 frame->key_frame = keyframe;
623 frame->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
626 bytestream2_init(&gB, buf, buf_size);
628 if (decode_555(&gB, (uint16_t *)c->rgb_pic, c->rgb_stride >> 1,
629 keyframe, avctx->width, avctx->height))
630 return AVERROR_INVALIDDATA;
632 buf_size -= bytestream2_tell(&gB);
636 ff_mss12_slicecontext_reset(&ctx->sc[0]);
638 ff_mss12_slicecontext_reset(&ctx->sc[1]);
641 if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
643 if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
644 c->rgb_pic, c->rgb_stride, c->pal, keyframe,
645 ctx->split_position, 0,
646 avctx->width, avctx->height))
651 if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
652 c->rgb_pic, c->rgb_stride, c->pal, keyframe,
653 ctx->split_position, 1,
654 avctx->width, avctx->height))
658 buf += get_bits_count(&gb) >> 3;
659 buf_size -= get_bits_count(&gb) >> 3;
660 } else if (!implicit_rect || wmv9_mask != -1) {
662 return AVERROR_INVALIDDATA;
663 bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
664 arith2_init(&acoder, &gB);
665 c->keyframe = keyframe;
666 if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[0], &acoder, 0, 0,
668 ctx->split_position))
669 return AVERROR_INVALIDDATA;
671 buf += arith2_get_consumed_bytes(&acoder);
672 buf_size -= arith2_get_consumed_bytes(&acoder);
673 if (c->slice_split) {
675 return AVERROR_INVALIDDATA;
676 bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
677 arith2_init(&acoder, &gB);
678 if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[1], &acoder, 0,
681 avctx->height - ctx->split_position))
682 return AVERROR_INVALIDDATA;
684 buf += arith2_get_consumed_bytes(&acoder);
685 buf_size -= arith2_get_consumed_bytes(&acoder);
688 memset(c->pal_pic, 0, c->pal_stride * avctx->height);
692 for (i = 0; i < used_rects; i++) {
693 int x = wmv9rects[i].x;
694 int y = wmv9rects[i].y;
695 int w = wmv9rects[i].w;
696 int h = wmv9rects[i].h;
697 if (wmv9rects[i].coded) {
698 int WMV9codedFrameSize;
699 if (buf_size < 4 || !(WMV9codedFrameSize = AV_RL24(buf)))
700 return AVERROR_INVALIDDATA;
701 if (ret = decode_wmv9(avctx, buf + 3, buf_size - 3,
702 x, y, w, h, wmv9_mask))
704 buf += WMV9codedFrameSize + 3;
705 buf_size -= WMV9codedFrameSize + 3;
707 uint8_t *dst = c->rgb_pic + y * c->rgb_stride + x * 3;
708 if (wmv9_mask != -1) {
709 ctx->dsp.mss2_gray_fill_masked(dst, c->rgb_stride,
711 c->pal_pic + y * c->pal_stride + x,
716 memset(dst, 0x80, w * 3);
717 dst += c->rgb_stride;
725 av_log(avctx, AV_LOG_WARNING, "buffer not fully consumed\n");
727 if (c->mvX < 0 || c->mvY < 0) {
728 av_frame_unref(ctx->last_pic);
729 ret = av_frame_ref(ctx->last_pic, frame);
739 static av_cold int wmv9_init(AVCodecContext *avctx)
741 VC1Context *v = avctx->priv_data;
746 if ((ret = ff_vc1_init_common(v)) < 0)
748 ff_vc1dsp_init(&v->vc1dsp);
750 v->profile = PROFILE_MAIN;
752 v->zz_8x4 = ff_wmv2_scantableA;
753 v->zz_4x8 = ff_wmv2_scantableB;
757 v->frmrtq_postproc = 7;
758 v->bitrtq_postproc = 31;
775 v->resync_marker = 0;
778 v->s.max_b_frames = avctx->max_b_frames = 0;
779 v->quantizer_mode = 0;
785 ff_vc1_init_transposed_scantables(v);
787 if ((ret = ff_msmpeg4_decode_init(avctx)) < 0 ||
788 (ret = ff_vc1_decode_init_alloc_tables(v)) < 0)
791 /* error concealment */
792 v->s.me.qpel_put = v->s.qdsp.put_qpel_pixels_tab;
793 v->s.me.qpel_avg = v->s.qdsp.avg_qpel_pixels_tab;
798 static av_cold int mss2_decode_end(AVCodecContext *avctx)
800 MSS2Context *const ctx = avctx->priv_data;
802 av_frame_free(&ctx->last_pic);
804 ff_mss12_decode_end(&ctx->c);
805 av_freep(&ctx->c.pal_pic);
806 av_freep(&ctx->c.last_pal_pic);
807 ff_vc1_decode_end(avctx);
812 static av_cold int mss2_decode_init(AVCodecContext *avctx)
814 MSS2Context * const ctx = avctx->priv_data;
815 MSS12Context *c = &ctx->c;
818 if (ret = ff_mss12_decode_init(c, 1, &ctx->sc[0], &ctx->sc[1]))
820 ctx->last_pic = av_frame_alloc();
821 c->pal_stride = c->mask_stride;
822 c->pal_pic = av_mallocz(c->pal_stride * avctx->height);
823 c->last_pal_pic = av_mallocz(c->pal_stride * avctx->height);
824 if (!c->pal_pic || !c->last_pal_pic || !ctx->last_pic) {
825 mss2_decode_end(avctx);
826 return AVERROR(ENOMEM);
828 if (ret = wmv9_init(avctx)) {
829 mss2_decode_end(avctx);
832 ff_mss2dsp_init(&ctx->dsp);
833 ff_qpeldsp_init(&ctx->qdsp);
835 avctx->pix_fmt = c->free_colours == 127 ? AV_PIX_FMT_RGB555
842 AVCodec ff_mss2_decoder = {
844 .long_name = NULL_IF_CONFIG_SMALL("MS Windows Media Video V9 Screen"),
845 .type = AVMEDIA_TYPE_VIDEO,
846 .id = AV_CODEC_ID_MSS2,
847 .priv_data_size = sizeof(MSS2Context),
848 .init = mss2_decode_init,
849 .close = mss2_decode_end,
850 .decode = mss2_decode_frame,
851 .capabilities = CODEC_CAP_DR1,