/* * RemotelyAnywhere Screen Capture 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 "libavutil/imgutils.h" #include "libavutil/opt.h" #include "avcodec.h" #include "bytestream.h" #include "internal.h" #include <zlib.h> #define KBND MKTAG('K', 'B', 'N', 'D') #define FINT MKTAG('F', 'I', 'N', 'T') #define INIT MKTAG('I', 'N', 'I', 'T') #define BNDL MKTAG('B', 'N', 'D', 'L') #define KFRM MKTAG('K', 'F', 'R', 'M') #define DLTA MKTAG('D', 'L', 'T', 'A') #define MOUS MKTAG('M', 'O', 'U', 'S') #define MPOS MKTAG('M', 'P', 'O', 'S') #define MOVE MKTAG('M', 'O', 'V', 'E') #define EMPT MKTAG('E', 'M', 'P', 'T') typedef struct RASCContext { AVClass *class; int skip_cursor; GetByteContext gb; uint8_t *delta; int delta_size; uint8_t *cursor; int cursor_size; unsigned cursor_w; unsigned cursor_h; unsigned cursor_x; unsigned cursor_y; int stride; int bpp; z_stream zstream; AVFrame *frame; AVFrame *frame1; AVFrame *frame2; } RASCContext; static void clear_plane(AVCodecContext *avctx, AVFrame *frame) { RASCContext *s = avctx->priv_data; uint8_t *dst = frame->data[0]; if (!dst) return; for (int y = 0; y < avctx->height; y++) { memset(dst, 0, avctx->width * s->bpp); dst += frame->linesize[0]; } } static void copy_plane(AVCodecContext *avctx, AVFrame *src, AVFrame *dst) { RASCContext *s = avctx->priv_data; uint8_t *srcp = src->data[0]; uint8_t *dstp = dst->data[0]; for (int y = 0; y < avctx->height; y++) { memcpy(dstp, srcp, s->stride); srcp += src->linesize[0]; dstp += dst->linesize[0]; } } static int init_frames(AVCodecContext *avctx) { RASCContext *s = avctx->priv_data; int ret; av_frame_unref(s->frame1); av_frame_unref(s->frame2); if ((ret = ff_get_buffer(avctx, s->frame1, 0)) < 0) return ret; if ((ret = ff_get_buffer(avctx, s->frame2, 0)) < 0) return ret; clear_plane(avctx, s->frame2); clear_plane(avctx, s->frame1); return 0; } static int decode_fint(AVCodecContext *avctx, const AVPacket *avpkt, unsigned size) { RASCContext *s = avctx->priv_data; GetByteContext *gb = &s->gb; unsigned w, h, fmt; int ret; if (bytestream2_peek_le32(gb) != 0x65) { if (!s->frame2->data[0] || !s->frame1->data[0]) return AVERROR_INVALIDDATA; clear_plane(avctx, s->frame2); clear_plane(avctx, s->frame1); return 0; } if (bytestream2_get_bytes_left(gb) < 72) return AVERROR_INVALIDDATA; bytestream2_skip(gb, 8); w = bytestream2_get_le32(gb); h = bytestream2_get_le32(gb); bytestream2_skip(gb, 30); fmt = bytestream2_get_le16(gb); bytestream2_skip(gb, 24); switch (fmt) { case 8: s->stride = FFALIGN(w, 4); s->bpp = 1; fmt = AV_PIX_FMT_PAL8; break; case 16: s->stride = w * 2; s->bpp = 2; fmt = AV_PIX_FMT_RGB555LE; break; case 32: s->stride = w * 4; s->bpp = 4; fmt = AV_PIX_FMT_BGR0; break; default: return AVERROR_INVALIDDATA; } ret = ff_set_dimensions(avctx, w, h); if (ret < 0) return ret; avctx->width = w; avctx->height = h; avctx->pix_fmt = fmt; ret = init_frames(avctx); if (ret < 0) return ret; if (avctx->pix_fmt == AV_PIX_FMT_PAL8) { uint32_t *pal = (uint32_t *)s->frame2->data[1]; for (int i = 0; i < 256; i++) pal[i] = bytestream2_get_le32(gb) | 0xFF000000u; } return 0; } static int decode_zlib(AVCodecContext *avctx, const AVPacket *avpkt, unsigned size, unsigned uncompressed_size) { RASCContext *s = avctx->priv_data; GetByteContext *gb = &s->gb; int zret; zret = inflateReset(&s->zstream); if (zret != Z_OK) { av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret); return AVERROR_EXTERNAL; } av_fast_padded_malloc(&s->delta, &s->delta_size, uncompressed_size); if (!s->delta) return AVERROR(ENOMEM); s->zstream.next_in = avpkt->data + bytestream2_tell(gb); s->zstream.avail_in = FFMIN(size, bytestream2_get_bytes_left(gb)); s->zstream.next_out = s->delta; s->zstream.avail_out = s->delta_size; zret = inflate(&s->zstream, Z_FINISH); if (zret != Z_STREAM_END) { av_log(avctx, AV_LOG_ERROR, "Inflate failed with return code: %d.\n", zret); return AVERROR_INVALIDDATA; } return 0; } static int decode_move(AVCodecContext *avctx, const AVPacket *avpkt, unsigned size) { RASCContext *s = avctx->priv_data; GetByteContext *gb = &s->gb; GetByteContext mc; unsigned pos, compression, nb_moves; unsigned uncompressed_size; int ret; pos = bytestream2_tell(gb); bytestream2_skip(gb, 8); nb_moves = bytestream2_get_le32(gb); bytestream2_skip(gb, 8); compression = bytestream2_get_le32(gb); if (nb_moves > INT32_MAX / 16 || nb_moves > avctx->width * avctx->height) return AVERROR_INVALIDDATA; uncompressed_size = 16 * nb_moves; if (compression == 1) { ret = decode_zlib(avctx, avpkt, size - (bytestream2_tell(gb) - pos), uncompressed_size); if (ret < 0) return ret; bytestream2_init(&mc, s->delta, uncompressed_size); } else if (compression == 0) { bytestream2_init(&mc, avpkt->data + bytestream2_tell(gb), bytestream2_get_bytes_left(gb)); } else if (compression == 2) { avpriv_request_sample(avctx, "compression %d", compression); return AVERROR_PATCHWELCOME; } else { return AVERROR_INVALIDDATA; } if (bytestream2_get_bytes_left(&mc) < uncompressed_size) return AVERROR_INVALIDDATA; for (int i = 0; i < nb_moves; i++) { int type, start_x, start_y, end_x, end_y, mov_x, mov_y; uint8_t *e2, *b1, *b2; int w, h; type = bytestream2_get_le16(&mc); start_x = bytestream2_get_le16(&mc); start_y = bytestream2_get_le16(&mc); end_x = bytestream2_get_le16(&mc); end_y = bytestream2_get_le16(&mc); mov_x = bytestream2_get_le16(&mc); mov_y = bytestream2_get_le16(&mc); bytestream2_skip(&mc, 2); if (start_x >= avctx->width || start_y >= avctx->height || end_x >= avctx->width || end_y >= avctx->height || mov_x >= avctx->width || mov_y >= avctx->height) { continue; } if (start_x >= end_x || start_y >= end_y) continue; w = end_x - start_x; h = end_y - start_y; if (mov_x + w > avctx->width || mov_y + h > avctx->height) continue; if (!s->frame2->data[0] || !s->frame1->data[0]) return AVERROR_INVALIDDATA; b1 = s->frame1->data[0] + s->frame1->linesize[0] * (start_y + h - 1) + start_x * s->bpp; b2 = s->frame2->data[0] + s->frame2->linesize[0] * (start_y + h - 1) + start_x * s->bpp; e2 = s->frame2->data[0] + s->frame2->linesize[0] * (mov_y + h - 1) + mov_x * s->bpp; if (type == 2) { for (int j = 0; j < h; j++) { memcpy(b1, b2, w * s->bpp); b1 -= s->frame1->linesize[0]; b2 -= s->frame2->linesize[0]; } } else if (type == 1) { for (int j = 0; j < h; j++) { memset(b2, 0, w * s->bpp); b2 -= s->frame2->linesize[0]; } } else if (type == 0) { uint8_t *buffer; av_fast_padded_malloc(&s->delta, &s->delta_size, w * h * s->bpp); buffer = s->delta; if (!buffer) return AVERROR(ENOMEM); for (int j = 0; j < h; j++) { memcpy(buffer + j * w * s->bpp, e2, w * s->bpp); e2 -= s->frame2->linesize[0]; } for (int j = 0; j < h; j++) { memcpy(b2, buffer + j * w * s->bpp, w * s->bpp); b2 -= s->frame2->linesize[0]; } } else { return AVERROR_INVALIDDATA; } } bytestream2_skip(gb, size - (bytestream2_tell(gb) - pos)); return 0; } #define NEXT_LINE \ if (cx >= w * s->bpp) { \ cx = 0; \ cy--; \ b1 -= s->frame1->linesize[0]; \ b2 -= s->frame2->linesize[0]; \ } \ len--; static int decode_dlta(AVCodecContext *avctx, const AVPacket *avpkt, unsigned size) { RASCContext *s = avctx->priv_data; GetByteContext *gb = &s->gb; GetByteContext dc; unsigned uncompressed_size, pos; unsigned x, y, w, h; int ret, cx, cy, compression; uint8_t *b1, *b2; pos = bytestream2_tell(gb); bytestream2_skip(gb, 12); uncompressed_size = bytestream2_get_le32(gb); x = bytestream2_get_le32(gb); y = bytestream2_get_le32(gb); w = bytestream2_get_le32(gb); h = bytestream2_get_le32(gb); if (x >= avctx->width || y >= avctx->height || w > avctx->width || h > avctx->height) return AVERROR_INVALIDDATA; if (x + w > avctx->width || y + h > avctx->height) return AVERROR_INVALIDDATA; bytestream2_skip(gb, 4); compression = bytestream2_get_le32(gb); if (compression == 1) { if (w * h * s->bpp * 3 < uncompressed_size) return AVERROR_INVALIDDATA; ret = decode_zlib(avctx, avpkt, size, uncompressed_size); if (ret < 0) return ret; bytestream2_init(&dc, s->delta, uncompressed_size); } else if (compression == 0) { if (bytestream2_get_bytes_left(gb) < uncompressed_size) return AVERROR_INVALIDDATA; bytestream2_init(&dc, avpkt->data + bytestream2_tell(gb), uncompressed_size); } else if (compression == 2) { avpriv_request_sample(avctx, "compression %d", compression); return AVERROR_PATCHWELCOME; } else { return AVERROR_INVALIDDATA; } if (!s->frame2->data[0] || !s->frame1->data[0]) return AVERROR_INVALIDDATA; b1 = s->frame1->data[0] + s->frame1->linesize[0] * (y + h - 1) + x * s->bpp; b2 = s->frame2->data[0] + s->frame2->linesize[0] * (y + h - 1) + x * s->bpp; cx = 0, cy = h; while (bytestream2_get_bytes_left(&dc) > 0) { int type = bytestream2_get_byte(&dc); int len = bytestream2_get_byte(&dc); unsigned fill; switch (type) { case 1: while (len > 0 && cy > 0) { cx++; NEXT_LINE } break; case 2: while (len > 0 && cy > 0) { int v0 = b1[cx]; int v1 = b2[cx]; b2[cx] = v0; b1[cx] = v1; cx++; NEXT_LINE } break; case 3: while (len > 0 && cy > 0) { fill = bytestream2_get_byte(&dc); b1[cx] = b2[cx]; b2[cx] = fill; cx++; NEXT_LINE } break; case 4: fill = bytestream2_get_byte(&dc); while (len > 0 && cy > 0) { AV_WL32(b1 + cx, AV_RL32(b2 + cx)); AV_WL32(b2 + cx, fill); cx++; NEXT_LINE } break; case 7: fill = bytestream2_get_le32(&dc); while (len > 0 && cy > 0) { AV_WL32(b1 + cx, AV_RL32(b2 + cx)); AV_WL32(b2 + cx, fill); cx += 4; NEXT_LINE } break; case 10: while (len > 0 && cy > 0) { cx += 4; NEXT_LINE } break; case 12: while (len > 0 && cy > 0) { unsigned v0, v1; v0 = AV_RL32(b2 + cx); v1 = AV_RL32(b1 + cx); AV_WL32(b2 + cx, v1); AV_WL32(b1 + cx, v0); cx += 4; NEXT_LINE } break; case 13: while (len > 0 && cy > 0) { fill = bytestream2_get_le32(&dc); AV_WL32(b1 + cx, AV_RL32(b2 + cx)); AV_WL32(b2 + cx, fill); cx += 4; NEXT_LINE } break; default: avpriv_request_sample(avctx, "runlen %d", type); return AVERROR_INVALIDDATA; } } bytestream2_skip(gb, size - (bytestream2_tell(gb) - pos)); return 0; } static int decode_kfrm(AVCodecContext *avctx, const AVPacket *avpkt, unsigned size) { RASCContext *s = avctx->priv_data; GetByteContext *gb = &s->gb; uint8_t *dst; unsigned pos; int zret, ret; pos = bytestream2_tell(gb); if (bytestream2_peek_le32(gb) == 0x65) { ret = decode_fint(avctx, avpkt, size); if (ret < 0) return ret; } if (!s->frame2->data[0]) return AVERROR_INVALIDDATA; zret = inflateReset(&s->zstream); if (zret != Z_OK) { av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret); return AVERROR_EXTERNAL; } s->zstream.next_in = avpkt->data + bytestream2_tell(gb); s->zstream.avail_in = bytestream2_get_bytes_left(gb); dst = s->frame2->data[0] + (avctx->height - 1) * s->frame2->linesize[0]; for (int i = 0; i < avctx->height; i++) { s->zstream.next_out = dst; s->zstream.avail_out = s->stride; zret = inflate(&s->zstream, Z_SYNC_FLUSH); if (zret != Z_OK && zret != Z_STREAM_END) { av_log(avctx, AV_LOG_ERROR, "Inflate failed with return code: %d.\n", zret); return AVERROR_INVALIDDATA; } dst -= s->frame2->linesize[0]; } dst = s->frame1->data[0] + (avctx->height - 1) * s->frame1->linesize[0]; for (int i = 0; i < avctx->height; i++) { s->zstream.next_out = dst; s->zstream.avail_out = s->stride; zret = inflate(&s->zstream, Z_SYNC_FLUSH); if (zret != Z_OK && zret != Z_STREAM_END) { av_log(avctx, AV_LOG_ERROR, "Inflate failed with return code: %d.\n", zret); return AVERROR_INVALIDDATA; } dst -= s->frame1->linesize[0]; } bytestream2_skip(gb, size - (bytestream2_tell(gb) - pos)); return 0; } static int decode_mous(AVCodecContext *avctx, const AVPacket *avpkt, unsigned size) { RASCContext *s = avctx->priv_data; GetByteContext *gb = &s->gb; unsigned w, h, pos, uncompressed_size; int ret; pos = bytestream2_tell(gb); bytestream2_skip(gb, 8); w = bytestream2_get_le32(gb); h = bytestream2_get_le32(gb); bytestream2_skip(gb, 12); uncompressed_size = bytestream2_get_le32(gb); if (w > avctx->width || h > avctx->height) return AVERROR_INVALIDDATA; if (uncompressed_size != 3 * w * h) return AVERROR_INVALIDDATA; av_fast_padded_malloc(&s->cursor, &s->cursor_size, uncompressed_size); if (!s->cursor) return AVERROR(ENOMEM); ret = decode_zlib(avctx, avpkt, size - (bytestream2_tell(gb) - pos), uncompressed_size); if (ret < 0) return ret; memcpy(s->cursor, s->delta, uncompressed_size); bytestream2_skip(gb, size - (bytestream2_tell(gb) - pos)); s->cursor_w = w; s->cursor_h = h; return 0; } static int decode_mpos(AVCodecContext *avctx, const AVPacket *avpkt, unsigned size) { RASCContext *s = avctx->priv_data; GetByteContext *gb = &s->gb; unsigned pos; pos = bytestream2_tell(gb); bytestream2_skip(gb, 8); s->cursor_x = bytestream2_get_le32(gb); s->cursor_y = bytestream2_get_le32(gb); bytestream2_skip(gb, size - (bytestream2_tell(gb) - pos)); return 0; } static void draw_cursor(AVCodecContext *avctx) { RASCContext *s = avctx->priv_data; uint8_t *dst, *pal; if (!s->cursor) return; if (s->cursor_x >= avctx->width || s->cursor_y >= avctx->height) return; if (s->cursor_x + s->cursor_w > avctx->width || s->cursor_y + s->cursor_h > avctx->height) return; if (avctx->pix_fmt == AV_PIX_FMT_PAL8) { pal = s->frame->data[1]; for (int i = 0; i < s->cursor_h; i++) { for (int j = 0; j < s->cursor_w; j++) { int cr = s->cursor[3 * s->cursor_w * (s->cursor_h - i - 1) + 3 * j + 0]; int cg = s->cursor[3 * s->cursor_w * (s->cursor_h - i - 1) + 3 * j + 1]; int cb = s->cursor[3 * s->cursor_w * (s->cursor_h - i - 1) + 3 * j + 2]; int best = INT_MAX; int index = 0; int dist; if (cr == s->cursor[0] && cg == s->cursor[1] && cb == s->cursor[2]) continue; dst = s->frame->data[0] + s->frame->linesize[0] * (s->cursor_y + i) + (s->cursor_x + j); for (int k = 0; k < 256; k++) { int pr = pal[k * 4 + 0]; int pg = pal[k * 4 + 1]; int pb = pal[k * 4 + 2]; dist = FFABS(cr - pr) + FFABS(cg - pg) + FFABS(cb - pb); if (dist < best) { best = dist; index = k; } } dst[0] = index; } } } else if (avctx->pix_fmt == AV_PIX_FMT_RGB555LE) { for (int i = 0; i < s->cursor_h; i++) { for (int j = 0; j < s->cursor_w; j++) { int cr = s->cursor[3 * s->cursor_w * (s->cursor_h - i - 1) + 3 * j + 0]; int cg = s->cursor[3 * s->cursor_w * (s->cursor_h - i - 1) + 3 * j + 1]; int cb = s->cursor[3 * s->cursor_w * (s->cursor_h - i - 1) + 3 * j + 2]; if (cr == s->cursor[0] && cg == s->cursor[1] && cb == s->cursor[2]) continue; cr >>= 3; cg >>=3; cb >>= 3; dst = s->frame->data[0] + s->frame->linesize[0] * (s->cursor_y + i) + 2 * (s->cursor_x + j); AV_WL16(dst, cr | cg << 5 | cb << 10); } } } else if (avctx->pix_fmt == AV_PIX_FMT_BGR0) { for (int i = 0; i < s->cursor_h; i++) { for (int j = 0; j < s->cursor_w; j++) { int cr = s->cursor[3 * s->cursor_w * (s->cursor_h - i - 1) + 3 * j + 0]; int cg = s->cursor[3 * s->cursor_w * (s->cursor_h - i - 1) + 3 * j + 1]; int cb = s->cursor[3 * s->cursor_w * (s->cursor_h - i - 1) + 3 * j + 2]; if (cr == s->cursor[0] && cg == s->cursor[1] && cb == s->cursor[2]) continue; dst = s->frame->data[0] + s->frame->linesize[0] * (s->cursor_y + i) + 4 * (s->cursor_x + j); dst[0] = cb; dst[1] = cg; dst[2] = cr; } } } } static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { RASCContext *s = avctx->priv_data; GetByteContext *gb = &s->gb; int ret, intra = 0; AVFrame *frame = data; bytestream2_init(gb, avpkt->data, avpkt->size); if (bytestream2_peek_le32(gb) == EMPT) return avpkt->size; s->frame = frame; while (bytestream2_get_bytes_left(gb) > 0) { unsigned type, size = 0; if (bytestream2_get_bytes_left(gb) < 8) return AVERROR_INVALIDDATA; type = bytestream2_get_le32(gb); if (type == KBND || type == BNDL) { intra = type == KBND; type = bytestream2_get_le32(gb); } size = bytestream2_get_le32(gb); if (bytestream2_get_bytes_left(gb) < size) return AVERROR_INVALIDDATA; switch (type) { case FINT: case INIT: ret = decode_fint(avctx, avpkt, size); break; case KFRM: ret = decode_kfrm(avctx, avpkt, size); break; case DLTA: ret = decode_dlta(avctx, avpkt, size); break; case MOVE: ret = decode_move(avctx, avpkt, size); break; case MOUS: ret = decode_mous(avctx, avpkt, size); break; case MPOS: ret = decode_mpos(avctx, avpkt, size); break; default: bytestream2_skip(gb, size); ret = 0; } if (ret < 0) return ret; } if (!s->frame2->data[0] || !s->frame1->data[0]) return AVERROR_INVALIDDATA; if ((ret = ff_get_buffer(avctx, s->frame, 0)) < 0) return ret; copy_plane(avctx, s->frame2, s->frame); if (avctx->pix_fmt == AV_PIX_FMT_PAL8) memcpy(s->frame->data[1], s->frame2->data[1], 1024); if (!s->skip_cursor) draw_cursor(avctx); s->frame->key_frame = intra; s->frame->pict_type = intra ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P; *got_frame = 1; return avpkt->size; } static av_cold int decode_init(AVCodecContext *avctx) { RASCContext *s = avctx->priv_data; int zret; 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->frame1 = av_frame_alloc(); s->frame2 = av_frame_alloc(); if (!s->frame1 || !s->frame2) return AVERROR(ENOMEM); return 0; } static av_cold int decode_close(AVCodecContext *avctx) { RASCContext *s = avctx->priv_data; av_freep(&s->cursor); s->cursor_size = 0; av_freep(&s->delta); s->delta_size = 0; av_frame_free(&s->frame1); av_frame_free(&s->frame2); inflateEnd(&s->zstream); return 0; } static void decode_flush(AVCodecContext *avctx) { RASCContext *s = avctx->priv_data; clear_plane(avctx, s->frame1); clear_plane(avctx, s->frame2); } static const AVOption options[] = { { "skip_cursor", "skip the cursor", offsetof(RASCContext, skip_cursor), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_VIDEO_PARAM }, { NULL }, }; static const AVClass rasc_decoder_class = { .class_name = "rasc decoder", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, }; const AVCodec ff_rasc_decoder = { .name = "rasc", .long_name = NULL_IF_CONFIG_SMALL("RemotelyAnywhere Screen Capture"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_RASC, .priv_data_size = sizeof(RASCContext), .init = decode_init, .close = decode_close, .decode = decode_frame, .flush = decode_flush, .capabilities = AV_CODEC_CAP_DR1, .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP, .priv_class = &rasc_decoder_class, };