| /* |
| * Microsoft Screen 4 (aka Microsoft Expression Encoder Screen) decoder |
| * Copyright (c) 2012 Konstantin Shishkov |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * Microsoft Screen 4 (aka Microsoft Titanium Screen 2, |
| * aka Microsoft Expression Encoder Screen) decoder |
| */ |
| |
| #include "libavutil/mem.h" |
| #include "libavutil/thread.h" |
| #include "libavutil/imgutils.h" |
| |
| #include "avcodec.h" |
| #include "bytestream.h" |
| #include "codec_internal.h" |
| #include "decode.h" |
| #include "get_bits.h" |
| #include "jpegtables.h" |
| #include "mss34dsp.h" |
| #include "unary.h" |
| |
| #define HEADER_SIZE 8 |
| |
| enum FrameType { |
| INTRA_FRAME = 0, |
| INTER_FRAME, |
| SKIP_FRAME |
| }; |
| |
| enum BlockType { |
| SKIP_BLOCK = 0, |
| DCT_BLOCK, |
| IMAGE_BLOCK, |
| }; |
| |
| enum CachePos { |
| LEFT = 0, |
| TOP_LEFT, |
| TOP, |
| }; |
| |
| static const uint8_t mss4_dc_vlc_lens[2][16] = { |
| { 0, 1, 5, 1, 1, 1, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0 }, |
| { 0, 3, 1, 1, 1, 1, 1, 1, 1, 2, 0, 0, 0, 0, 0, 0 } |
| }; |
| |
| static const uint8_t vec_len_syms[2][4] = { |
| { 4, 2, 3, 1 }, |
| { 4, 1, 2, 3 } |
| }; |
| |
| static const uint8_t mss4_vec_entry_vlc_lens[2][16] = { |
| { 0, 2, 2, 3, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, |
| { 0, 1, 5, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } |
| }; |
| |
| static const uint8_t mss4_vec_entry_vlc_syms[2][9] = { |
| { 0, 7, 6, 5, 8, 4, 3, 1, 2 }, |
| { 0, 2, 3, 4, 5, 6, 7, 1, 8 } |
| }; |
| |
| #define MAX_ENTRIES 162 |
| |
| typedef struct MSS4Context { |
| AVFrame *pic; |
| |
| int block[64]; |
| uint8_t imgbuf[3][16 * 16]; |
| |
| int quality; |
| uint16_t quant_mat[2][64]; |
| |
| int *prev_dc[3]; |
| ptrdiff_t dc_stride[3]; |
| int dc_cache[4][4]; |
| |
| int prev_vec[3][4]; |
| } MSS4Context; |
| |
| static VLC dc_vlc[2], ac_vlc[2]; |
| static VLC vec_entry_vlc[2]; |
| |
| static av_cold void mss4_init_vlc(VLC *vlc, unsigned *offset, |
| const uint8_t *lens, const uint8_t *syms) |
| { |
| static VLCElem vlc_buf[2146]; |
| uint8_t bits[MAX_ENTRIES]; |
| int i, j; |
| int idx = 0; |
| |
| for (i = 0; i < 16; i++) { |
| for (j = 0; j < lens[i]; j++) { |
| bits[idx] = i + 1; |
| idx++; |
| } |
| } |
| |
| vlc->table = &vlc_buf[*offset]; |
| vlc->table_allocated = FF_ARRAY_ELEMS(vlc_buf) - *offset; |
| ff_vlc_init_from_lengths(vlc, FFMIN(bits[idx - 1], 9), idx, |
| bits, 1, syms, 1, 1, |
| 0, VLC_INIT_STATIC_OVERLONG, NULL); |
| *offset += vlc->table_size; |
| } |
| |
| static av_cold void mss4_init_vlcs(void) |
| { |
| for (unsigned i = 0, offset = 0; i < 2; i++) { |
| mss4_init_vlc(&dc_vlc[i], &offset, mss4_dc_vlc_lens[i], NULL); |
| mss4_init_vlc(&ac_vlc[i], &offset, |
| i ? ff_mjpeg_bits_ac_chrominance + 1 |
| : ff_mjpeg_bits_ac_luminance + 1, |
| i ? ff_mjpeg_val_ac_chrominance |
| : ff_mjpeg_val_ac_luminance); |
| mss4_init_vlc(&vec_entry_vlc[i], &offset, mss4_vec_entry_vlc_lens[i], |
| mss4_vec_entry_vlc_syms[i]); |
| } |
| } |
| |
| /* This function returns values in the range |
| * (-range + 1; -range/2] U [range/2; range - 1) |
| * i.e. |
| * nbits = 0 -> 0 |
| * nbits = 1 -> -1, 1 |
| * nbits = 2 -> -3, -2, 2, 3 |
| */ |
| static av_always_inline int get_coeff_bits(GetBitContext *gb, int nbits) |
| { |
| int val; |
| |
| if (!nbits) |
| return 0; |
| |
| val = get_bits(gb, nbits); |
| if (val < (1 << (nbits - 1))) |
| val -= (1 << nbits) - 1; |
| |
| return val; |
| } |
| |
| static inline int get_coeff(GetBitContext *gb, const VLC *vlc, |
| int nb_bits, int max_depth) |
| { |
| int val = get_vlc2(gb, vlc->table, nb_bits, max_depth); |
| |
| return get_coeff_bits(gb, val); |
| } |
| |
| static int mss4_decode_dct(GetBitContext *gb, VLC *dc_vlc, VLC *ac_vlc, |
| int *block, int *dc_cache, |
| int bx, int by, uint16_t *quant_mat) |
| { |
| int skip, val, pos = 1, zz_pos, dc; |
| |
| memset(block, 0, sizeof(*block) * 64); |
| |
| dc = get_coeff(gb, dc_vlc, dc_vlc->bits, 2); |
| // DC prediction is the same as in MSS3 |
| if (by) { |
| if (bx) { |
| int l, tl, t; |
| |
| l = dc_cache[LEFT]; |
| tl = dc_cache[TOP_LEFT]; |
| t = dc_cache[TOP]; |
| |
| if (FFABS(t - tl) <= FFABS(l - tl)) |
| dc += l; |
| else |
| dc += t; |
| } else { |
| dc += dc_cache[TOP]; |
| } |
| } else if (bx) { |
| dc += dc_cache[LEFT]; |
| } |
| dc_cache[LEFT] = dc; |
| block[0] = dc * quant_mat[0]; |
| |
| while (pos < 64) { |
| val = get_vlc2(gb, ac_vlc->table, 9, 2); |
| if (!val) |
| return 0; |
| if (val == -1) |
| return -1; |
| if (val == 0xF0) { |
| pos += 16; |
| continue; |
| } |
| skip = val >> 4; |
| val = get_coeff_bits(gb, val & 0xF); |
| pos += skip; |
| if (pos >= 64) |
| return -1; |
| |
| zz_pos = ff_zigzag_direct[pos]; |
| block[zz_pos] = val * quant_mat[zz_pos]; |
| pos++; |
| } |
| |
| return pos == 64 ? 0 : -1; |
| } |
| |
| static int mss4_decode_dct_block(MSS4Context *c, GetBitContext *gb, |
| uint8_t *dst[3], int mb_x, int mb_y) |
| { |
| int i, j, k, ret; |
| uint8_t *out = dst[0]; |
| |
| for (j = 0; j < 2; j++) { |
| for (i = 0; i < 2; i++) { |
| int xpos = mb_x * 2 + i; |
| c->dc_cache[j][TOP_LEFT] = c->dc_cache[j][TOP]; |
| c->dc_cache[j][TOP] = c->prev_dc[0][mb_x * 2 + i]; |
| ret = mss4_decode_dct(gb, &dc_vlc[0], &ac_vlc[0], c->block, |
| c->dc_cache[j], |
| xpos, mb_y * 2 + j, c->quant_mat[0]); |
| if (ret) |
| return ret; |
| c->prev_dc[0][mb_x * 2 + i] = c->dc_cache[j][LEFT]; |
| |
| ff_mss34_dct_put(out + xpos * 8, c->pic->linesize[0], |
| c->block); |
| } |
| out += 8 * c->pic->linesize[0]; |
| } |
| |
| for (i = 1; i < 3; i++) { |
| c->dc_cache[i + 1][TOP_LEFT] = c->dc_cache[i + 1][TOP]; |
| c->dc_cache[i + 1][TOP] = c->prev_dc[i][mb_x]; |
| ret = mss4_decode_dct(gb, &dc_vlc[1], &ac_vlc[1], |
| c->block, c->dc_cache[i + 1], mb_x, mb_y, |
| c->quant_mat[1]); |
| if (ret) |
| return ret; |
| c->prev_dc[i][mb_x] = c->dc_cache[i + 1][LEFT]; |
| |
| ff_mss34_dct_put(c->imgbuf[i], 8, c->block); |
| out = dst[i] + mb_x * 16; |
| // Since the DCT block is coded as YUV420 and the whole frame as YUV444, |
| // we need to scale chroma. |
| for (j = 0; j < 16; j++) { |
| for (k = 0; k < 8; k++) |
| AV_WN16A(out + k * 2, c->imgbuf[i][k + (j & ~1) * 4] * 0x101); |
| out += c->pic->linesize[i]; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static void read_vec_pos(GetBitContext *gb, int *vec_pos, int *sel_flag, |
| int *sel_len, int *prev) |
| { |
| int i, y_flag = 0; |
| |
| for (i = 2; i >= 0; i--) { |
| if (!sel_flag[i]) { |
| vec_pos[i] = 0; |
| continue; |
| } |
| if ((!i && !y_flag) || get_bits1(gb)) { |
| if (sel_len[i] > 0) { |
| int pval = prev[i]; |
| vec_pos[i] = get_bits(gb, sel_len[i]); |
| if (vec_pos[i] >= pval) |
| vec_pos[i]++; |
| } else { |
| vec_pos[i] = !prev[i]; |
| } |
| y_flag = 1; |
| } else { |
| vec_pos[i] = prev[i]; |
| } |
| } |
| } |
| |
| static int get_value_cached(GetBitContext *gb, int vec_pos, uint8_t *vec, |
| int vec_size, int component, int shift, int *prev) |
| { |
| if (vec_pos < vec_size) |
| return vec[vec_pos]; |
| if (!get_bits1(gb)) |
| return prev[component]; |
| prev[component] = get_bits(gb, 8 - shift) << shift; |
| return prev[component]; |
| } |
| |
| #define MKVAL(vals) ((vals)[0] | ((vals)[1] << 3) | ((vals)[2] << 6)) |
| |
| /* Image mode - the hardest to comprehend MSS4 coding mode. |
| * |
| * In this mode all three 16x16 blocks are coded together with a method |
| * remotely similar to the methods employed in MSS1-MSS3. |
| * The idea is that every component has a vector of 1-4 most common symbols |
| * and an escape mode for reading new value from the bitstream. Decoding |
| * consists of retrieving pixel values from the vector or reading new ones |
| * from the bitstream; depending on flags read from the bitstream, these vector |
| * positions can be updated or reused from the state of the previous line |
| * or previous pixel. |
| */ |
| static int mss4_decode_image_block(MSS4Context *ctx, GetBitContext *gb, |
| uint8_t *picdst[3], int mb_x, int mb_y) |
| { |
| uint8_t vec[3][4]; |
| int vec_len[3]; |
| int sel_len[3], sel_flag[3]; |
| int i, j, k, mode, split; |
| int prev_vec1 = 0, prev_split = 0; |
| int vals[3] = { 0 }; |
| int prev_pix[3] = { 0 }; |
| int prev_mode[16] = { 0 }; |
| uint8_t *dst[3]; |
| |
| const int val_shift = ctx->quality == 100 ? 0 : 2; |
| |
| for (i = 0; i < 3; i++) |
| dst[i] = ctx->imgbuf[i]; |
| |
| for (i = 0; i < 3; i++) { |
| vec_len[i] = vec_len_syms[!!i][get_unary(gb, 0, 3)]; |
| for (j = 0; j < vec_len[i]; j++) { |
| vec[i][j] = get_coeff(gb, &vec_entry_vlc[!!i], 5, 1); |
| vec[i][j] += ctx->prev_vec[i][j]; |
| ctx->prev_vec[i][j] = vec[i][j]; |
| } |
| sel_flag[i] = vec_len[i] > 1; |
| sel_len[i] = vec_len[i] > 2 ? vec_len[i] - 2 : 0; |
| } |
| |
| for (j = 0; j < 16; j++) { |
| if (get_bits1(gb)) { |
| split = 0; |
| if (get_bits1(gb)) { |
| prev_mode[0] = 0; |
| vals[0] = vals[1] = vals[2] = 0; |
| mode = 2; |
| } else { |
| mode = get_bits1(gb); |
| if (mode) |
| split = get_bits(gb, 4); |
| } |
| for (i = 0; i < 16; i++) { |
| if (mode <= 1) { |
| vals[0] = prev_mode[i] & 7; |
| vals[1] = (prev_mode[i] >> 3) & 7; |
| vals[2] = prev_mode[i] >> 6; |
| if (mode == 1 && i == split) { |
| read_vec_pos(gb, vals, sel_flag, sel_len, vals); |
| } |
| } else if (mode == 2) { |
| if (get_bits1(gb)) |
| read_vec_pos(gb, vals, sel_flag, sel_len, vals); |
| } |
| for (k = 0; k < 3; k++) |
| *dst[k]++ = get_value_cached(gb, vals[k], vec[k], |
| vec_len[k], k, |
| val_shift, prev_pix); |
| prev_mode[i] = MKVAL(vals); |
| } |
| } else { |
| if (get_bits1(gb)) { |
| split = get_bits(gb, 4); |
| if (split >= prev_split) |
| split++; |
| prev_split = split; |
| } else { |
| split = prev_split; |
| } |
| if (split) { |
| vals[0] = prev_mode[0] & 7; |
| vals[1] = (prev_mode[0] >> 3) & 7; |
| vals[2] = prev_mode[0] >> 6; |
| for (i = 0; i < 3; i++) { |
| for (k = 0; k < split; k++) { |
| *dst[i]++ = get_value_cached(gb, vals[i], vec[i], |
| vec_len[i], i, val_shift, |
| prev_pix); |
| prev_mode[k] = MKVAL(vals); |
| } |
| } |
| } |
| |
| if (split != 16) { |
| vals[0] = prev_vec1 & 7; |
| vals[1] = (prev_vec1 >> 3) & 7; |
| vals[2] = prev_vec1 >> 6; |
| if (get_bits1(gb)) { |
| read_vec_pos(gb, vals, sel_flag, sel_len, vals); |
| prev_vec1 = MKVAL(vals); |
| } |
| for (i = 0; i < 3; i++) { |
| for (k = 0; k < 16 - split; k++) { |
| *dst[i]++ = get_value_cached(gb, vals[i], vec[i], |
| vec_len[i], i, val_shift, |
| prev_pix); |
| prev_mode[split + k] = MKVAL(vals); |
| } |
| } |
| } |
| } |
| } |
| |
| for (i = 0; i < 3; i++) |
| for (j = 0; j < 16; j++) |
| memcpy(picdst[i] + mb_x * 16 + j * ctx->pic->linesize[i], |
| ctx->imgbuf[i] + j * 16, 16); |
| |
| return 0; |
| } |
| |
| static inline void mss4_update_dc_cache(MSS4Context *c, int mb_x) |
| { |
| int i; |
| |
| c->dc_cache[0][TOP] = c->prev_dc[0][mb_x * 2 + 1]; |
| c->dc_cache[0][LEFT] = 0; |
| c->dc_cache[1][TOP] = 0; |
| c->dc_cache[1][LEFT] = 0; |
| |
| for (i = 0; i < 2; i++) |
| c->prev_dc[0][mb_x * 2 + i] = 0; |
| |
| for (i = 1; i < 3; i++) { |
| c->dc_cache[i + 1][TOP] = c->prev_dc[i][mb_x]; |
| c->dc_cache[i + 1][LEFT] = 0; |
| c->prev_dc[i][mb_x] = 0; |
| } |
| } |
| |
| static int mss4_decode_frame(AVCodecContext *avctx, AVFrame *rframe, |
| int *got_frame, AVPacket *avpkt) |
| { |
| const uint8_t *buf = avpkt->data; |
| int buf_size = avpkt->size; |
| MSS4Context *c = avctx->priv_data; |
| GetBitContext gb; |
| GetByteContext bc; |
| uint8_t *dst[3]; |
| int width, height, quality, frame_type; |
| int x, y, i, mb_width, mb_height, blk_type; |
| int ret; |
| |
| if (buf_size < HEADER_SIZE) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Frame should have at least %d bytes, got %d instead\n", |
| HEADER_SIZE, buf_size); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| bytestream2_init(&bc, buf, buf_size); |
| width = bytestream2_get_be16(&bc); |
| height = bytestream2_get_be16(&bc); |
| bytestream2_skip(&bc, 2); |
| quality = bytestream2_get_byte(&bc); |
| frame_type = bytestream2_get_byte(&bc); |
| |
| if (width > avctx->width || |
| height != avctx->height) { |
| av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d\n", |
| width, height); |
| return AVERROR_INVALIDDATA; |
| } |
| if (av_image_check_size2(width, height, avctx->max_pixels, AV_PIX_FMT_NONE, 0, avctx) < 0) |
| return AVERROR_INVALIDDATA; |
| |
| if (quality < 1 || quality > 100) { |
| av_log(avctx, AV_LOG_ERROR, "Invalid quality setting %d\n", quality); |
| return AVERROR_INVALIDDATA; |
| } |
| if ((frame_type & ~3) || frame_type == 3) { |
| av_log(avctx, AV_LOG_ERROR, "Invalid frame type %d\n", frame_type); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if (frame_type != SKIP_FRAME && !bytestream2_get_bytes_left(&bc)) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Empty frame found but it is not a skip frame.\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| mb_width = FFALIGN(width, 16) >> 4; |
| mb_height = FFALIGN(height, 16) >> 4; |
| |
| if (frame_type != SKIP_FRAME && 8*buf_size < 8*HEADER_SIZE + mb_width*mb_height) |
| return AVERROR_INVALIDDATA; |
| |
| if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0) |
| return ret; |
| if (frame_type == INTRA_FRAME) |
| c->pic->flags |= AV_FRAME_FLAG_KEY; |
| else |
| c->pic->flags &= ~AV_FRAME_FLAG_KEY; |
| c->pic->pict_type = (frame_type == INTRA_FRAME) ? AV_PICTURE_TYPE_I |
| : AV_PICTURE_TYPE_P; |
| if (frame_type == SKIP_FRAME) { |
| *got_frame = 1; |
| if ((ret = av_frame_ref(rframe, c->pic)) < 0) |
| return ret; |
| |
| return buf_size; |
| } |
| |
| if (c->quality != quality) { |
| c->quality = quality; |
| for (i = 0; i < 2; i++) |
| ff_mss34_gen_quant_mat(c->quant_mat[i], quality, !i); |
| } |
| |
| if ((ret = init_get_bits8(&gb, buf + HEADER_SIZE, buf_size - HEADER_SIZE)) < 0) |
| return ret; |
| dst[0] = c->pic->data[0]; |
| dst[1] = c->pic->data[1]; |
| dst[2] = c->pic->data[2]; |
| |
| memset(c->prev_vec, 0, sizeof(c->prev_vec)); |
| for (y = 0; y < mb_height; y++) { |
| memset(c->dc_cache, 0, sizeof(c->dc_cache)); |
| for (x = 0; x < mb_width; x++) { |
| blk_type = decode012(&gb); |
| switch (blk_type) { |
| case DCT_BLOCK: |
| if (mss4_decode_dct_block(c, &gb, dst, x, y) < 0) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Error decoding DCT block %d,%d\n", |
| x, y); |
| return AVERROR_INVALIDDATA; |
| } |
| break; |
| case IMAGE_BLOCK: |
| if (mss4_decode_image_block(c, &gb, dst, x, y) < 0) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Error decoding VQ block %d,%d\n", |
| x, y); |
| return AVERROR_INVALIDDATA; |
| } |
| break; |
| case SKIP_BLOCK: |
| if (frame_type == INTRA_FRAME) { |
| av_log(avctx, AV_LOG_ERROR, "Skip block in intra frame\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| break; |
| } |
| if (blk_type != DCT_BLOCK) |
| mss4_update_dc_cache(c, x); |
| } |
| dst[0] += c->pic->linesize[0] * 16; |
| dst[1] += c->pic->linesize[1] * 16; |
| dst[2] += c->pic->linesize[2] * 16; |
| } |
| |
| if ((ret = av_frame_ref(rframe, c->pic)) < 0) |
| return ret; |
| |
| *got_frame = 1; |
| |
| return buf_size; |
| } |
| |
| static av_cold int mss4_decode_end(AVCodecContext *avctx) |
| { |
| MSS4Context * const c = avctx->priv_data; |
| int i; |
| |
| av_frame_free(&c->pic); |
| for (i = 0; i < 3; i++) |
| av_freep(&c->prev_dc[i]); |
| |
| return 0; |
| } |
| |
| static av_cold int mss4_decode_init(AVCodecContext *avctx) |
| { |
| static AVOnce init_static_once = AV_ONCE_INIT; |
| MSS4Context * const c = avctx->priv_data; |
| int i; |
| |
| for (i = 0; i < 3; i++) { |
| c->dc_stride[i] = FFALIGN(avctx->width, 16) >> (2 + !!i); |
| c->prev_dc[i] = av_malloc_array(c->dc_stride[i], sizeof(**c->prev_dc)); |
| if (!c->prev_dc[i]) { |
| av_log(avctx, AV_LOG_ERROR, "Cannot allocate buffer\n"); |
| return AVERROR(ENOMEM); |
| } |
| } |
| |
| c->pic = av_frame_alloc(); |
| if (!c->pic) |
| return AVERROR(ENOMEM); |
| |
| avctx->pix_fmt = AV_PIX_FMT_YUV444P; |
| |
| ff_thread_once(&init_static_once, mss4_init_vlcs); |
| |
| return 0; |
| } |
| |
| const FFCodec ff_mts2_decoder = { |
| .p.name = "mts2", |
| CODEC_LONG_NAME("MS Expression Encoder Screen"), |
| .p.type = AVMEDIA_TYPE_VIDEO, |
| .p.id = AV_CODEC_ID_MTS2, |
| .priv_data_size = sizeof(MSS4Context), |
| .init = mss4_decode_init, |
| .close = mss4_decode_end, |
| FF_CODEC_DECODE_CB(mss4_decode_frame), |
| .p.capabilities = AV_CODEC_CAP_DR1, |
| .caps_internal = FF_CODEC_CAP_INIT_CLEANUP, |
| }; |
