| /* |
| * Copyright (c) 2019 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 <stdint.h> |
| #include <zlib.h> |
| |
| #include "libavutil/frame.h" |
| #include "libavutil/error.h" |
| #include "libavutil/log.h" |
| |
| #include "avcodec.h" |
| #include "bytestream.h" |
| #include "codec.h" |
| #include "internal.h" |
| #include "packet.h" |
| #include "png.h" |
| #include "pngdsp.h" |
| |
| typedef struct LSCRContext { |
| PNGDSPContext dsp; |
| AVCodecContext *avctx; |
| |
| AVFrame *last_picture; |
| uint8_t *buffer; |
| int buffer_size; |
| uint8_t *crow_buf; |
| int crow_size; |
| uint8_t *last_row; |
| unsigned int last_row_size; |
| |
| GetByteContext gb; |
| uint8_t *image_buf; |
| int image_linesize; |
| int row_size; |
| int cur_h; |
| int y; |
| |
| z_stream zstream; |
| } LSCRContext; |
| |
| static void handle_row(LSCRContext *s) |
| { |
| uint8_t *ptr, *last_row; |
| |
| ptr = s->image_buf + s->image_linesize * s->y; |
| if (s->y == 0) |
| last_row = s->last_row; |
| else |
| last_row = ptr - s->image_linesize; |
| |
| ff_png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1, |
| last_row, s->row_size, 3); |
| |
| s->y++; |
| } |
| |
| static int decode_idat(LSCRContext *s, int length) |
| { |
| int ret; |
| s->zstream.avail_in = FFMIN(length, bytestream2_get_bytes_left(&s->gb)); |
| s->zstream.next_in = s->gb.buffer; |
| bytestream2_skip(&s->gb, length); |
| |
| /* decode one line if possible */ |
| while (s->zstream.avail_in > 0) { |
| ret = inflate(&s->zstream, Z_PARTIAL_FLUSH); |
| if (ret != Z_OK && ret != Z_STREAM_END) { |
| av_log(s->avctx, AV_LOG_ERROR, "inflate returned error %d\n", ret); |
| return AVERROR_EXTERNAL; |
| } |
| if (s->zstream.avail_out == 0) { |
| if (s->y < s->cur_h) { |
| handle_row(s); |
| } |
| s->zstream.avail_out = s->crow_size; |
| s->zstream.next_out = s->crow_buf; |
| } |
| if (ret == Z_STREAM_END && s->zstream.avail_in > 0) { |
| av_log(s->avctx, AV_LOG_WARNING, |
| "%d undecompressed bytes left in buffer\n", s->zstream.avail_in); |
| return 0; |
| } |
| } |
| return 0; |
| } |
| |
| static int decode_frame_lscr(AVCodecContext *avctx, |
| void *data, int *got_frame, |
| AVPacket *avpkt) |
| { |
| LSCRContext *const s = avctx->priv_data; |
| GetByteContext *gb = &s->gb; |
| AVFrame *frame = s->last_picture; |
| int ret, nb_blocks, offset = 0; |
| |
| if (avpkt->size < 2) |
| return AVERROR_INVALIDDATA; |
| if (avpkt->size == 2) |
| return 0; |
| |
| bytestream2_init(gb, avpkt->data, avpkt->size); |
| |
| nb_blocks = bytestream2_get_le16(gb); |
| if (bytestream2_get_bytes_left(gb) < 2 + nb_blocks * (12 + 8)) |
| return AVERROR_INVALIDDATA; |
| |
| ret = ff_reget_buffer(avctx, frame, |
| nb_blocks ? 0 : FF_REGET_BUFFER_FLAG_READONLY); |
| if (ret < 0) |
| return ret; |
| |
| for (int b = 0; b < nb_blocks; b++) { |
| int x, y, x2, y2, w, h, left; |
| uint32_t csize, size; |
| |
| s->zstream.zalloc = ff_png_zalloc; |
| s->zstream.zfree = ff_png_zfree; |
| s->zstream.opaque = NULL; |
| |
| if ((ret = inflateInit(&s->zstream)) != Z_OK) { |
| av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret); |
| ret = AVERROR_EXTERNAL; |
| goto end; |
| } |
| |
| bytestream2_seek(gb, 2 + b * 12, SEEK_SET); |
| |
| x = bytestream2_get_le16(gb); |
| y = bytestream2_get_le16(gb); |
| x2 = bytestream2_get_le16(gb); |
| y2 = bytestream2_get_le16(gb); |
| w = x2-x; |
| s->cur_h = h = y2-y; |
| |
| if (w <= 0 || x < 0 || x >= avctx->width || w + x > avctx->width || |
| h <= 0 || y < 0 || y >= avctx->height || h + y > avctx->height) { |
| ret = AVERROR_INVALIDDATA; |
| goto end; |
| } |
| |
| size = bytestream2_get_le32(gb); |
| |
| frame->key_frame = (nb_blocks == 1) && |
| (w == avctx->width) && |
| (h == avctx->height) && |
| (x == 0) && (y == 0); |
| |
| bytestream2_seek(gb, 2 + nb_blocks * 12 + offset, SEEK_SET); |
| csize = bytestream2_get_be32(gb); |
| if (bytestream2_get_le32(gb) != MKTAG('I', 'D', 'A', 'T')) { |
| ret = AVERROR_INVALIDDATA; |
| goto end; |
| } |
| |
| offset += size; |
| left = size; |
| |
| s->y = 0; |
| s->row_size = w * 3; |
| |
| av_fast_padded_malloc(&s->buffer, &s->buffer_size, s->row_size + 16); |
| if (!s->buffer) { |
| ret = AVERROR(ENOMEM); |
| goto end; |
| } |
| |
| av_fast_padded_malloc(&s->last_row, &s->last_row_size, s->row_size); |
| if (!s->last_row) { |
| ret = AVERROR(ENOMEM); |
| goto end; |
| } |
| |
| s->crow_size = w * 3 + 1; |
| s->crow_buf = s->buffer + 15; |
| s->zstream.avail_out = s->crow_size; |
| s->zstream.next_out = s->crow_buf; |
| s->image_buf = frame->data[0] + (avctx->height - y - 1) * frame->linesize[0] + x * 3; |
| s->image_linesize =-frame->linesize[0]; |
| |
| while (left > 16) { |
| ret = decode_idat(s, csize); |
| if (ret < 0) |
| goto end; |
| left -= csize + 16; |
| if (left > 16) { |
| bytestream2_skip(gb, 4); |
| csize = bytestream2_get_be32(gb); |
| if (bytestream2_get_le32(gb) != MKTAG('I', 'D', 'A', 'T')) { |
| ret = AVERROR_INVALIDDATA; |
| goto end; |
| } |
| } |
| } |
| |
| inflateEnd(&s->zstream); |
| } |
| |
| frame->pict_type = frame->key_frame ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P; |
| |
| if ((ret = av_frame_ref(data, frame)) < 0) |
| return ret; |
| |
| *got_frame = 1; |
| end: |
| inflateEnd(&s->zstream); |
| |
| if (ret < 0) |
| return ret; |
| return avpkt->size; |
| } |
| |
| static int lscr_decode_close(AVCodecContext *avctx) |
| { |
| LSCRContext *s = avctx->priv_data; |
| |
| av_frame_free(&s->last_picture); |
| av_freep(&s->buffer); |
| av_freep(&s->last_row); |
| |
| return 0; |
| } |
| |
| static int lscr_decode_init(AVCodecContext *avctx) |
| { |
| LSCRContext *s = avctx->priv_data; |
| |
| avctx->color_range = AVCOL_RANGE_JPEG; |
| avctx->pix_fmt = AV_PIX_FMT_BGR24; |
| |
| s->avctx = avctx; |
| s->last_picture = av_frame_alloc(); |
| if (!s->last_picture) |
| return AVERROR(ENOMEM); |
| |
| ff_pngdsp_init(&s->dsp); |
| |
| return 0; |
| } |
| |
| static void lscr_decode_flush(AVCodecContext *avctx) |
| { |
| LSCRContext *s = avctx->priv_data; |
| av_frame_unref(s->last_picture); |
| } |
| |
| AVCodec ff_lscr_decoder = { |
| .name = "lscr", |
| .long_name = NULL_IF_CONFIG_SMALL("LEAD Screen Capture"), |
| .type = AVMEDIA_TYPE_VIDEO, |
| .id = AV_CODEC_ID_LSCR, |
| .priv_data_size = sizeof(LSCRContext), |
| .init = lscr_decode_init, |
| .close = lscr_decode_close, |
| .decode = decode_frame_lscr, |
| .flush = lscr_decode_flush, |
| .capabilities = AV_CODEC_CAP_DR1, |
| .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, |
| }; |