| /* |
| * TechSmith Screen Codec 2 (aka Dora) 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 |
| * TechSmith Screen Codec 2 decoder |
| */ |
| |
| #include <inttypes.h> |
| |
| #define BITSTREAM_READER_LE |
| #include "avcodec.h" |
| #include "bytestream.h" |
| #include "get_bits.h" |
| #include "internal.h" |
| #include "mathops.h" |
| #include "tscc2data.h" |
| |
| typedef struct TSCC2Context { |
| AVCodecContext *avctx; |
| AVFrame *pic; |
| int mb_width, mb_height; |
| uint8_t *slice_quants; |
| int quant[2]; |
| int q[2][3]; |
| GetBitContext gb; |
| |
| VLC dc_vlc, nc_vlc[NUM_VLC_SETS], ac_vlc[NUM_VLC_SETS]; |
| int block[16]; |
| } TSCC2Context; |
| |
| static av_cold void free_vlcs(TSCC2Context *c) |
| { |
| int i; |
| |
| ff_free_vlc(&c->dc_vlc); |
| for (i = 0; i < NUM_VLC_SETS; i++) { |
| ff_free_vlc(c->nc_vlc + i); |
| ff_free_vlc(c->ac_vlc + i); |
| } |
| } |
| |
| static av_cold int init_vlcs(TSCC2Context *c) |
| { |
| int i, ret; |
| |
| ret = ff_init_vlc_sparse(&c->dc_vlc, 9, DC_VLC_COUNT, |
| tscc2_dc_vlc_bits, 1, 1, |
| tscc2_dc_vlc_codes, 2, 2, |
| tscc2_dc_vlc_syms, 2, 2, INIT_VLC_LE); |
| if (ret) |
| return ret; |
| |
| for (i = 0; i < NUM_VLC_SETS; i++) { |
| ret = ff_init_vlc_sparse(c->nc_vlc + i, 9, 16, |
| tscc2_nc_vlc_bits[i], 1, 1, |
| tscc2_nc_vlc_codes[i], 2, 2, |
| tscc2_nc_vlc_syms, 1, 1, INIT_VLC_LE); |
| if (ret) { |
| free_vlcs(c); |
| return ret; |
| } |
| ret = ff_init_vlc_sparse(c->ac_vlc + i, 9, tscc2_ac_vlc_sizes[i], |
| tscc2_ac_vlc_bits[i], 1, 1, |
| tscc2_ac_vlc_codes[i], 2, 2, |
| tscc2_ac_vlc_syms[i], 2, 2, INIT_VLC_LE); |
| if (ret) { |
| free_vlcs(c); |
| return ret; |
| } |
| } |
| |
| return 0; |
| } |
| |
| #define DEQUANT(val, q) (((q) * (val) + 0x80) >> 8) |
| #define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \ |
| OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3)); \ |
| OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1)); \ |
| OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s1)); \ |
| OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3)); \ |
| |
| #define COL_OP(a, b) a = (b) |
| #define ROW_OP(a, b) a = ((b) + 0x20) >> 6 |
| |
| static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride) |
| { |
| int i; |
| int tblk[4 * 4]; |
| int t0, t1, t2, t3; |
| |
| for (i = 0; i < 4; i++) { |
| t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]); |
| t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]); |
| t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]); |
| t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]); |
| DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i], |
| tblk[2 * 4 + i], tblk[3 * 4 + i], |
| t0, t1, t2, t3, COL_OP); |
| } |
| for (i = 0; i < 4; i++) { |
| DCT1D(dst[0], dst[1], dst[2], dst[3], |
| tblk[i * 4 + 0], tblk[i * 4 + 1], |
| tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP); |
| dst += stride; |
| } |
| } |
| |
| static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set, |
| uint8_t *dst, int stride, int plane) |
| { |
| GetBitContext *gb = &c->gb; |
| int prev_dc, dc, nc, ac, bpos, val; |
| int i, j, k, l; |
| |
| if (get_bits1(gb)) { |
| if (get_bits1(gb)) { |
| val = get_bits(gb, 8); |
| for (i = 0; i < 8; i++, dst += stride) |
| memset(dst, val, 16); |
| } else { |
| if (get_bits_left(gb) < 16 * 8 * 8) |
| return AVERROR_INVALIDDATA; |
| for (i = 0; i < 8; i++) { |
| for (j = 0; j < 16; j++) |
| dst[j] = get_bits(gb, 8); |
| dst += stride; |
| } |
| } |
| return 0; |
| } |
| |
| prev_dc = 0; |
| for (j = 0; j < 2; j++) { |
| for (k = 0; k < 4; k++) { |
| if (!(j | k)) { |
| dc = get_bits(gb, 8); |
| } else { |
| dc = get_vlc2(gb, c->dc_vlc.table, 9, 2); |
| if (dc == -1) |
| return AVERROR_INVALIDDATA; |
| if (dc == 0x100) |
| dc = get_bits(gb, 8); |
| } |
| dc = (dc + prev_dc) & 0xFF; |
| prev_dc = dc; |
| c->block[0] = dc; |
| |
| nc = get_vlc2(gb, c->nc_vlc[vlc_set].table, 9, 1); |
| if (nc == -1) |
| return AVERROR_INVALIDDATA; |
| |
| bpos = 1; |
| memset(c->block + 1, 0, 15 * sizeof(*c->block)); |
| for (l = 0; l < nc; l++) { |
| ac = get_vlc2(gb, c->ac_vlc[vlc_set].table, 9, 2); |
| if (ac == -1) |
| return AVERROR_INVALIDDATA; |
| if (ac == 0x1000) |
| ac = get_bits(gb, 12); |
| bpos += ac & 0xF; |
| if (bpos >= 16) |
| return AVERROR_INVALIDDATA; |
| val = sign_extend(ac >> 4, 8); |
| c->block[ff_zigzag_scan[bpos++]] = val; |
| } |
| tscc2_idct4_put(c->block, q, dst + k * 4, stride); |
| } |
| dst += 4 * stride; |
| } |
| return 0; |
| } |
| |
| static int tscc2_decode_slice(TSCC2Context *c, int mb_y, |
| const uint8_t *buf, int buf_size) |
| { |
| int i, mb_x, q, ret; |
| int off; |
| |
| if ((ret = init_get_bits8(&c->gb, buf, buf_size)) < 0) |
| return ret; |
| |
| for (mb_x = 0; mb_x < c->mb_width; mb_x++) { |
| q = c->slice_quants[mb_x + c->mb_width * mb_y]; |
| |
| if (q == 0 || q == 3) // skip block |
| continue; |
| for (i = 0; i < 3; i++) { |
| off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i]; |
| ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2, |
| c->pic->data[i] + off, c->pic->linesize[i], i); |
| if (ret) |
| return ret; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int tscc2_decode_frame(AVCodecContext *avctx, void *data, |
| int *got_frame, AVPacket *avpkt) |
| { |
| const uint8_t *buf = avpkt->data; |
| int buf_size = avpkt->size; |
| TSCC2Context *c = avctx->priv_data; |
| GetByteContext gb; |
| uint32_t frame_type, size; |
| int i, val, len, pos = 0; |
| int num_mb = c->mb_width * c->mb_height; |
| int ret; |
| |
| bytestream2_init(&gb, buf, buf_size); |
| frame_type = bytestream2_get_byte(&gb); |
| if (frame_type > 1) { |
| av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %"PRIu32"\n", |
| frame_type); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if (frame_type == 0) { |
| // Skip duplicate frames |
| return buf_size; |
| } |
| |
| if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0) { |
| return ret; |
| } |
| |
| if (bytestream2_get_bytes_left(&gb) < 4) { |
| av_log(avctx, AV_LOG_ERROR, "Frame is too short\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| c->quant[0] = bytestream2_get_byte(&gb); |
| c->quant[1] = bytestream2_get_byte(&gb); |
| if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 || |
| c->quant[1] < 2 || c->quant[1] > NUM_VLC_SETS + 1) { |
| av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n", |
| c->quant[0], c->quant[1]); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| for (i = 0; i < 3; i++) { |
| c->q[0][i] = tscc2_quants[c->quant[0] - 2][i]; |
| c->q[1][i] = tscc2_quants[c->quant[1] - 2][i]; |
| } |
| |
| bytestream2_skip(&gb, 1); |
| |
| size = bytestream2_get_le32(&gb); |
| if (size > bytestream2_get_bytes_left(&gb)) { |
| av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| for (i = 0; i < size; i++) { |
| val = bytestream2_get_byte(&gb); |
| len = val & 0x3F; |
| val >>= 6; |
| if (pos + len > num_mb) { |
| av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| memset(c->slice_quants + pos, val, len); |
| pos += len; |
| } |
| if (pos < num_mb) { |
| av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n", |
| pos, num_mb); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| for (i = 0; i < c->mb_height; i++) { |
| size = bytestream2_peek_byte(&gb); |
| if (size & 1) { |
| size = bytestream2_get_byte(&gb) - 1; |
| } else { |
| size = bytestream2_get_le32(&gb) >> 1; |
| } |
| if (!size) { |
| int skip_row = 1, j, off = i * c->mb_width; |
| for (j = 0; j < c->mb_width; j++) { |
| if (c->slice_quants[off + j] == 1 || |
| c->slice_quants[off + j] == 2) { |
| skip_row = 0; |
| break; |
| } |
| } |
| if (!skip_row) { |
| av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| } |
| if (bytestream2_get_bytes_left(&gb) < size) { |
| av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%"PRIu32"/%u)\n", |
| size, bytestream2_get_bytes_left(&gb)); |
| return AVERROR_INVALIDDATA; |
| } |
| ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size); |
| if (ret) { |
| av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i); |
| return ret; |
| } |
| bytestream2_skip(&gb, size); |
| } |
| |
| *got_frame = 1; |
| if ((ret = av_frame_ref(data, c->pic)) < 0) |
| return ret; |
| |
| /* always report that the buffer was completely consumed */ |
| return buf_size; |
| } |
| |
| static av_cold int tscc2_decode_end(AVCodecContext *avctx) |
| { |
| TSCC2Context * const c = avctx->priv_data; |
| |
| av_frame_free(&c->pic); |
| av_freep(&c->slice_quants); |
| free_vlcs(c); |
| |
| return 0; |
| } |
| |
| static av_cold int tscc2_decode_init(AVCodecContext *avctx) |
| { |
| TSCC2Context * const c = avctx->priv_data; |
| int ret; |
| |
| c->avctx = avctx; |
| |
| avctx->pix_fmt = AV_PIX_FMT_YUV444P; |
| |
| if ((ret = init_vlcs(c)) < 0) { |
| av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n"); |
| return ret; |
| } |
| |
| c->mb_width = FFALIGN(avctx->width, 16) >> 4; |
| c->mb_height = FFALIGN(avctx->height, 8) >> 3; |
| c->slice_quants = av_malloc(c->mb_width * c->mb_height); |
| if (!c->slice_quants) { |
| av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n"); |
| free_vlcs(c); |
| return AVERROR(ENOMEM); |
| } |
| |
| c->pic = av_frame_alloc(); |
| if (!c->pic) { |
| tscc2_decode_end(avctx); |
| return AVERROR(ENOMEM); |
| } |
| |
| return 0; |
| } |
| |
| AVCodec ff_tscc2_decoder = { |
| .name = "tscc2", |
| .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Codec 2"), |
| .type = AVMEDIA_TYPE_VIDEO, |
| .id = AV_CODEC_ID_TSCC2, |
| .priv_data_size = sizeof(TSCC2Context), |
| .init = tscc2_decode_init, |
| .close = tscc2_decode_end, |
| .decode = tscc2_decode_frame, |
| .capabilities = AV_CODEC_CAP_DR1, |
| }; |
