2 * innoHeim/Rsupport Screen Capture Codec
3 * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * innoHeim/Rsupport Screen Capture Codec decoder
28 * Lossless codec, data stored in tiles, with optional deflate compression.
30 * Header contains the number of tiles in a frame with the tile coordinates,
31 * and it can be deflated or not. Similarly, pixel data comes after the header
32 * and a variable size value, and it can be deflated or just raw.
41 #include "libavutil/imgutils.h"
42 #include "libavutil/internal.h"
45 #include "bytestream.h"
55 typedef struct RsccContext {
59 unsigned int tiles_size;
61 /* zlib interaction */
62 uint8_t *inflated_buf;
66 static av_cold int rscc_init(AVCodecContext *avctx)
68 RsccContext *ctx = avctx->priv_data;
70 /* These needs to be set to estimate uncompressed buffer */
71 int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
73 av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
74 avctx->width, avctx->height);
78 /* Allocate reference frame */
79 ctx->reference = av_frame_alloc();
81 return AVERROR(ENOMEM);
83 avctx->pix_fmt = AV_PIX_FMT_BGRA;
85 /* Store the value to check for keyframes */
86 ctx->inflated_size = avctx->width * avctx->height * 4;
88 /* Allocate maximum size possible, a full frame */
89 ctx->inflated_buf = av_malloc(ctx->inflated_size);
90 if (!ctx->inflated_buf)
91 return AVERROR(ENOMEM);
96 static av_cold int rscc_close(AVCodecContext *avctx)
98 RsccContext *ctx = avctx->priv_data;
100 av_freep(&ctx->tiles);
101 av_freep(&ctx->inflated_buf);
102 av_frame_free(&ctx->reference);
107 static int rscc_decode_frame(AVCodecContext *avctx, void *data,
108 int *got_frame, AVPacket *avpkt)
110 RsccContext *ctx = avctx->priv_data;
111 GetByteContext *gbc = &ctx->gbc;
112 GetByteContext tiles_gbc;
113 AVFrame *frame = data;
114 const uint8_t *pixels, *raw;
115 uint8_t *inflated_tiles = NULL;
116 int tiles_nb, packed_size, pixel_size = 0;
119 bytestream2_init(gbc, avpkt->data, avpkt->size);
122 if (bytestream2_get_bytes_left(gbc) < 12) {
123 av_log(avctx, AV_LOG_ERROR, "Packet too small (%d)\n", avpkt->size);
124 return AVERROR_INVALIDDATA;
127 /* Read number of tiles, and allocate the array */
128 tiles_nb = bytestream2_get_le16(gbc);
129 av_fast_malloc(&ctx->tiles, &ctx->tiles_size,
130 tiles_nb * sizeof(*ctx->tiles));
132 ret = AVERROR(ENOMEM);
136 av_log(avctx, AV_LOG_DEBUG, "Frame with %d tiles.\n", tiles_nb);
138 /* When there are more than 5 tiles, they are packed together with
139 * a size header. When that size does not match the number of tiles
140 * times the tile size, it means it needs to be inflated as well */
142 uLongf packed_tiles_size;
145 packed_tiles_size = bytestream2_get_byte(gbc);
147 packed_tiles_size = bytestream2_get_le16(gbc);
149 ff_dlog(avctx, "packed tiles of size %lu.\n", packed_tiles_size);
151 /* If necessary, uncompress tiles, and hijack the bytestream reader */
152 if (packed_tiles_size != tiles_nb * TILE_SIZE) {
153 uLongf length = tiles_nb * TILE_SIZE;
154 inflated_tiles = av_malloc(length);
155 if (!inflated_tiles) {
156 ret = AVERROR(ENOMEM);
160 ret = uncompress(inflated_tiles, &length,
161 gbc->buffer, packed_tiles_size);
163 av_log(avctx, AV_LOG_ERROR, "Tile deflate error %d.\n", ret);
164 ret = AVERROR_UNKNOWN;
168 /* Skip the compressed tile section in the main byte reader,
169 * and point it to read the newly uncompressed data */
170 bytestream2_skip(gbc, packed_tiles_size);
171 bytestream2_init(&tiles_gbc, inflated_tiles, length);
176 /* Fill in array of tiles, keeping track of how many pixels are updated */
177 for (i = 0; i < tiles_nb; i++) {
178 ctx->tiles[i].x = bytestream2_get_le16(gbc);
179 ctx->tiles[i].w = bytestream2_get_le16(gbc);
180 ctx->tiles[i].y = bytestream2_get_le16(gbc);
181 ctx->tiles[i].h = bytestream2_get_le16(gbc);
183 pixel_size += ctx->tiles[i].w * ctx->tiles[i].h * 4;
185 ff_dlog(avctx, "tile %d orig(%d,%d) %dx%d.\n", i,
186 ctx->tiles[i].x, ctx->tiles[i].y,
187 ctx->tiles[i].w, ctx->tiles[i].h);
189 if (ctx->tiles[i].w == 0 || ctx->tiles[i].h == 0) {
190 av_log(avctx, AV_LOG_ERROR,
191 "invalid tile %d at (%d.%d) with size %dx%d.\n", i,
192 ctx->tiles[i].x, ctx->tiles[i].y,
193 ctx->tiles[i].w, ctx->tiles[i].h);
194 ret = AVERROR_INVALIDDATA;
196 } else if (ctx->tiles[i].x + ctx->tiles[i].w > avctx->width ||
197 ctx->tiles[i].y + ctx->tiles[i].h > avctx->height) {
198 av_log(avctx, AV_LOG_ERROR,
199 "out of bounds tile %d at (%d.%d) with size %dx%d.\n", i,
200 ctx->tiles[i].x, ctx->tiles[i].y,
201 ctx->tiles[i].w, ctx->tiles[i].h);
202 ret = AVERROR_INVALIDDATA;
207 /* Reset the reader in case it had been modified before */
210 /* Extract how much pixel data the tiles contain */
211 if (pixel_size < 0x100)
212 packed_size = bytestream2_get_byte(gbc);
213 else if (pixel_size < 0x10000)
214 packed_size = bytestream2_get_le16(gbc);
215 else if (pixel_size < 0x1000000)
216 packed_size = bytestream2_get_le24(gbc);
218 packed_size = bytestream2_get_le32(gbc);
220 ff_dlog(avctx, "pixel_size %d packed_size %d.\n", pixel_size, packed_size);
222 /* Get pixels buffer, it may be deflated or just raw */
223 if (pixel_size == packed_size) {
224 if (bytestream2_get_bytes_left(gbc) < pixel_size) {
225 av_log(avctx, AV_LOG_ERROR, "Insufficient input for %d\n", pixel_size);
226 ret = AVERROR_INVALIDDATA;
229 pixels = gbc->buffer;
231 uLongf len = ctx->inflated_size;
232 ret = uncompress(ctx->inflated_buf, &len, gbc->buffer, packed_size);
234 av_log(avctx, AV_LOG_ERROR, "Pixel deflate error %d.\n", ret);
235 ret = AVERROR_UNKNOWN;
238 pixels = ctx->inflated_buf;
241 /* Allocate when needed */
242 ret = ff_reget_buffer(avctx, ctx->reference);
246 /* Pointer to actual pixels, will be updated when data is consumed */
248 for (i = 0; i < tiles_nb; i++) {
249 uint8_t *dst = ctx->reference->data[0] + ctx->reference->linesize[0] *
250 (avctx->height - ctx->tiles[i].y - 1) +
252 av_image_copy_plane(dst, -1 * ctx->reference->linesize[0],
253 raw, ctx->tiles[i].w * 4,
254 ctx->tiles[i].w * 4, ctx->tiles[i].h);
255 raw += ctx->tiles[i].w * 4 * ctx->tiles[i].h;
258 /* Frame is ready to be output */
259 ret = av_frame_ref(frame, ctx->reference);
263 /* Keyframe when the number of pixels updated matches the whole surface */
264 if (pixel_size == ctx->inflated_size) {
265 frame->pict_type = AV_PICTURE_TYPE_I;
266 frame->key_frame = 1;
268 frame->pict_type = AV_PICTURE_TYPE_P;
273 av_free(inflated_tiles);
277 AVCodec ff_rscc_decoder = {
279 .long_name = NULL_IF_CONFIG_SMALL("innoHeim/Rsupport Screen Capture Codec"),
280 .type = AVMEDIA_TYPE_VIDEO,
281 .id = AV_CODEC_ID_RSCC,
283 .decode = rscc_decode_frame,
285 .priv_data_size = sizeof(RsccContext),
286 .capabilities = AV_CODEC_CAP_DR1,
287 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
288 FF_CODEC_CAP_INIT_CLEANUP,