/* * MatchWare Screen Capture Codec decoder * * Copyright (c) 2018 Paul B Mahol * * 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 */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include "avcodec.h" #include "bytestream.h" #include "internal.h" #include <zlib.h> typedef struct MWSCContext { unsigned int decomp_size; uint8_t *decomp_buf; z_stream zstream; AVFrame *prev_frame; } MWSCContext; static int rle_uncompress(GetByteContext *gb, PutByteContext *pb, GetByteContext *gbp, int width, int height, int stride, int pb_linesize, int gbp_linesize) { int intra = 1, w = 0; bytestream2_seek_p(pb, (height - 1) * pb_linesize, SEEK_SET); while (bytestream2_get_bytes_left(gb) > 0) { uint32_t fill = bytestream2_get_le24(gb); unsigned run = bytestream2_get_byte(gb); if (run == 0) { run = bytestream2_get_le32(gb); for (int j = 0; j < run; j++, w++) { if (w == width) { w = 0; bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR); } bytestream2_put_le24(pb, fill); } } else if (run == 255) { int pos = bytestream2_tell_p(pb); bytestream2_seek(gbp, pos, SEEK_SET); for (int j = 0; j < fill; j++, w++) { if (w == width) { w = 0; bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR); bytestream2_seek(gbp, -(gbp_linesize + stride), SEEK_CUR); } bytestream2_put_le24(pb, bytestream2_get_le24(gbp)); } intra = 0; } else { for (int j = 0; j < run; j++, w++) { if (w == width) { w = 0; bytestream2_seek_p(pb, -(pb_linesize + stride), SEEK_CUR); } bytestream2_put_le24(pb, fill); } } } return intra; } static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { MWSCContext *s = avctx->priv_data; AVFrame *frame = data; uint8_t *buf = avpkt->data; int buf_size = avpkt->size; GetByteContext gb; GetByteContext gbp; PutByteContext pb; int ret; ret = inflateReset(&s->zstream); if (ret != Z_OK) { av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret); return AVERROR_EXTERNAL; } s->zstream.next_in = buf; s->zstream.avail_in = buf_size; s->zstream.next_out = s->decomp_buf; s->zstream.avail_out = s->decomp_size; ret = inflate(&s->zstream, Z_FINISH); if (ret != Z_STREAM_END) { av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret); return AVERROR_EXTERNAL; } if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) return ret; bytestream2_init(&gb, s->decomp_buf, s->zstream.total_out); bytestream2_init(&gbp, s->prev_frame->data[0], avctx->height * s->prev_frame->linesize[0]); bytestream2_init_writer(&pb, frame->data[0], avctx->height * frame->linesize[0]); frame->key_frame = rle_uncompress(&gb, &pb, &gbp, avctx->width, avctx->height, avctx->width * 3, frame->linesize[0], s->prev_frame->linesize[0]); frame->pict_type = frame->key_frame ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P; av_frame_unref(s->prev_frame); if ((ret = av_frame_ref(s->prev_frame, frame)) < 0) return ret; *got_frame = 1; return avpkt->size; } static av_cold int decode_init(AVCodecContext *avctx) { MWSCContext *s = avctx->priv_data; int64_t size; int zret; avctx->pix_fmt = AV_PIX_FMT_BGR24; size = 32LL * avctx->height * avctx->width; if (size >= INT32_MAX) return AVERROR_INVALIDDATA; s->decomp_size = size; if (!(s->decomp_buf = av_malloc(s->decomp_size))) return AVERROR(ENOMEM); s->zstream.zalloc = Z_NULL; s->zstream.zfree = Z_NULL; s->zstream.opaque = Z_NULL; zret = inflateInit(&s->zstream); if (zret != Z_OK) { av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret); return AVERROR_EXTERNAL; } s->prev_frame = av_frame_alloc(); if (!s->prev_frame) return AVERROR(ENOMEM); return 0; } static av_cold int decode_close(AVCodecContext *avctx) { MWSCContext *s = avctx->priv_data; av_frame_free(&s->prev_frame); av_freep(&s->decomp_buf); s->decomp_size = 0; inflateEnd(&s->zstream); return 0; } AVCodec ff_mwsc_decoder = { .name = "mwsc", .long_name = NULL_IF_CONFIG_SMALL("MatchWare Screen Capture Codec"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_MWSC, .priv_data_size = sizeof(MWSCContext), .init = decode_init, .close = decode_close, .decode = decode_frame, .capabilities = AV_CODEC_CAP_DR1, .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP, };