From 5b7e3a195dcc09235d9d82327846e420090a781d Mon Sep 17 00:00:00 2001 From: Kostya Shishkov Date: Sat, 7 Jul 2012 13:21:52 +0200 Subject: MS Expression Encoder Screen decoder --- libavcodec/mss4.c | 682 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 682 insertions(+) create mode 100644 libavcodec/mss4.c (limited to 'libavcodec/mss4.c') diff --git a/libavcodec/mss4.c b/libavcodec/mss4.c new file mode 100644 index 0000000000..2742d05a5c --- /dev/null +++ b/libavcodec/mss4.c @@ -0,0 +1,682 @@ +/* + * Microsoft Screen 4 (aka Microsoft Expression Encoder Screen) decoder + * Copyright (c) 2012 Konstantin Shishkov + * + * This file is part of Libav. + * + * Libav 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. + * + * Libav 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 Libav; 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 "avcodec.h" +#include "bytestream.h" +#include "dsputil.h" +#include "get_bits.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 mss4_ac_vlc_lens[2][16] = { + { 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 125 }, + { 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 119 } +}; + +static const uint8_t mss4_ac_vlc_syms[2][162] = { + { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, + 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07, + 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xA1, 0x08, + 0x23, 0x42, 0xB1, 0xC1, 0x15, 0x52, 0xD1, 0xF0, + 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0A, 0x16, + 0x17, 0x18, 0x19, 0x1A, 0x25, 0x26, 0x27, 0x28, + 0x29, 0x2A, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, + 0x3A, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, + 0x4A, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, + 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, + 0x6A, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, + 0x7A, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, + 0x8A, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, + 0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, + 0xA8, 0xA9, 0xAA, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, + 0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3, 0xC4, 0xC5, + 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xD2, 0xD3, 0xD4, + 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xE1, 0xE2, + 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, + 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, + 0xF9, 0xFA }, + { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, + 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71, + 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, + 0xA1, 0xB1, 0xC1, 0x09, 0x23, 0x33, 0x52, 0xF0, + 0x15, 0x62, 0x72, 0xD1, 0x0A, 0x16, 0x24, 0x34, + 0xE1, 0x25, 0xF1, 0x17, 0x18, 0x19, 0x1A, 0x26, + 0x27, 0x28, 0x29, 0x2A, 0x35, 0x36, 0x37, 0x38, + 0x39, 0x3A, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, + 0x49, 0x4A, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, + 0x59, 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, + 0x69, 0x6A, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, + 0x79, 0x7A, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, + 0x88, 0x89, 0x8A, 0x92, 0x93, 0x94, 0x95, 0x96, + 0x97, 0x98, 0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5, + 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xB2, 0xB3, 0xB4, + 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3, + 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xD2, + 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, + 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, + 0xEA, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, + 0xF9, 0xFA } +}; + +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; + DSPContext dsp; + + VLC dc_vlc[2], ac_vlc[2]; + VLC vec_entry_vlc[2]; + int block[64]; + uint8_t imgbuf[3][16 * 16]; + + int quality; + uint16_t quant_mat[2][64]; + + int *prev_dc[3]; + int dc_stride[3]; + int dc_cache[4][4]; + + int prev_vec[3][4]; +} MSS4Context; + +static av_cold int mss4_init_vlc(VLC *vlc, const uint8_t *lens, + const uint8_t *syms, int num_syms) +{ + uint8_t bits[MAX_ENTRIES]; + uint16_t codes[MAX_ENTRIES]; + int i, j; + int prefix = 0, max_bits = 0, idx = 0; + + for (i = 0; i < 16; i++) { + for (j = 0; j < lens[i]; j++) { + bits[idx] = i + 1; + codes[idx] = prefix++; + max_bits = i + 1; + idx++; + } + prefix <<= 1; + } + + return ff_init_vlc_sparse(vlc, FFMIN(max_bits, 9), num_syms, bits, 1, 1, + codes, 2, 2, syms, 1, 1, 0); +} + +static av_cold int mss4_init_vlcs(MSS4Context *ctx) +{ + int ret, i; + + for (i = 0; i < 2; i++) { + ret = mss4_init_vlc(&ctx->dc_vlc[i], mss4_dc_vlc_lens[i], NULL, 12); + if (ret) + return ret; + ret = mss4_init_vlc(&ctx->ac_vlc[i], mss4_ac_vlc_lens[i], + mss4_ac_vlc_syms[i], 162); + if (ret) + return ret; + ret = mss4_init_vlc(&ctx->vec_entry_vlc[i], mss4_vec_entry_vlc_lens[i], + mss4_vec_entry_vlc_syms[i], 9); + if (ret) + return ret; + } + return 0; +} + +static av_cold void mss4_free_vlcs(MSS4Context *ctx) +{ + int i; + + for (i = 0; i < 2; i++) { + ff_free_vlc(&ctx->dc_vlc[i]); + ff_free_vlc(&ctx->ac_vlc[i]); + ff_free_vlc(&ctx->vec_entry_vlc[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, VLC *vlc) +{ + int val = get_vlc2(gb, vlc->table, vlc->bits, 2); + + 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 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, c->dc_vlc, c->ac_vlc, 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, c->dc_vlc + 1, c->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, &ctx->vec_entry_vlc[!!i]); + 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, void *data, int *data_size, + 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 (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; + } + + c->pic.reference = 3; + c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | + FF_BUFFER_HINTS_PRESERVE | + FF_BUFFER_HINTS_REUSABLE; + if ((ret = avctx->reget_buffer(avctx, &c->pic)) < 0) { + av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); + return ret; + } + c->pic.key_frame = (frame_type == INTRA_FRAME); + c->pic.pict_type = (frame_type == INTRA_FRAME) ? AV_PICTURE_TYPE_I + : AV_PICTURE_TYPE_P; + if (frame_type == SKIP_FRAME) { + *data_size = sizeof(AVFrame); + *(AVFrame*)data = c->pic; + + 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); + } + + init_get_bits(&gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE) * 8); + + mb_width = FFALIGN(width, 16) >> 4; + mb_height = FFALIGN(height, 16) >> 4; + 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; + } + + *data_size = sizeof(AVFrame); + *(AVFrame*)data = c->pic; + + return buf_size; +} + +static av_cold int mss4_decode_init(AVCodecContext *avctx) +{ + MSS4Context * const c = avctx->priv_data; + int i; + + if (mss4_init_vlcs(c)) { + av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n"); + mss4_free_vlcs(c); + return AVERROR(ENOMEM); + } + for (i = 0; i < 3; i++) { + c->dc_stride[i] = FFALIGN(avctx->width, 16) >> (2 + !!i); + c->prev_dc[i] = av_malloc(sizeof(**c->prev_dc) * c->dc_stride[i]); + if (!c->prev_dc[i]) { + av_log(avctx, AV_LOG_ERROR, "Cannot allocate buffer\n"); + mss4_free_vlcs(c); + return AVERROR(ENOMEM); + } + } + + avctx->pix_fmt = PIX_FMT_YUV444P; + avctx->coded_frame = &c->pic; + + return 0; +} + +static av_cold int mss4_decode_end(AVCodecContext *avctx) +{ + MSS4Context * const c = avctx->priv_data; + int i; + + if (c->pic.data[0]) + avctx->release_buffer(avctx, &c->pic); + for (i = 0; i < 3; i++) + av_freep(&c->prev_dc[i]); + mss4_free_vlcs(c); + + return 0; +} + +AVCodec ff_mts2_decoder = { + .name = "mts2", + .type = AVMEDIA_TYPE_VIDEO, + .id = CODEC_ID_MTS2, + .priv_data_size = sizeof(MSS4Context), + .init = mss4_decode_init, + .close = mss4_decode_end, + .decode = mss4_decode_frame, + .capabilities = CODEC_CAP_DR1, + .long_name = NULL_IF_CONFIG_SMALL("MS Expression Encoder Screen"), +}; -- cgit v1.2.3