2 * innoHeim/Rsupport Screen Capture Codec
3 * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
5 * This file is part of Libav.
7 * Libav 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 * Libav 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 Libav; 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.
34 * Supports: PAL8, BGRA, BGR24, RGB555, RGB8
41 #include "libavutil/imgutils.h"
42 #include "libavutil/internal.h"
45 #include "bytestream.h"
55 typedef struct RsccContext {
59 unsigned int tiles_size;
62 uint8_t palette[AVPALETTE_SIZE];
64 /* zlib interaction */
65 uint8_t *inflated_buf;
69 static av_cold int rscc_init(AVCodecContext *avctx)
71 RsccContext *ctx = avctx->priv_data;
73 /* These needs to be set to estimate uncompressed buffer */
74 int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
76 av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
77 avctx->width, avctx->height);
81 /* Allocate reference frame */
82 ctx->reference = av_frame_alloc();
84 return AVERROR(ENOMEM);
86 /* Get pixel format and the size of the pixel */
87 if (avctx->codec_tag == MKTAG('I', 'S', 'C', 'C')) {
88 avctx->pix_fmt = AV_PIX_FMT_BGRA;
89 ctx->component_size = 4;
90 } else if (avctx->codec_tag == MKTAG('R', 'S', 'C', 'C')) {
91 ctx->component_size = avctx->bits_per_coded_sample / 8;
92 switch (avctx->bits_per_coded_sample) {
94 avctx->pix_fmt = AV_PIX_FMT_PAL8;
97 avctx->pix_fmt = AV_PIX_FMT_RGB555LE;
100 avctx->pix_fmt = AV_PIX_FMT_BGR24;
103 avctx->pix_fmt = AV_PIX_FMT_BGRA;
106 av_log(avctx, AV_LOG_ERROR, "Invalid bits per pixel value (%d)\n",
107 avctx->bits_per_coded_sample);
108 return AVERROR_INVALIDDATA;
111 av_log(avctx, AV_LOG_ERROR, "Invalid codec tag\n");
112 return AVERROR_INVALIDDATA;
115 /* Store the value to check for keyframes */
116 ctx->inflated_size = avctx->width * avctx->height * ctx->component_size;
118 /* Allocate maximum size possible, a full frame */
119 ctx->inflated_buf = av_malloc(ctx->inflated_size);
120 if (!ctx->inflated_buf)
121 return AVERROR(ENOMEM);
126 static av_cold int rscc_close(AVCodecContext *avctx)
128 RsccContext *ctx = avctx->priv_data;
130 av_freep(&ctx->tiles);
131 av_freep(&ctx->inflated_buf);
132 av_frame_free(&ctx->reference);
137 static int rscc_decode_frame(AVCodecContext *avctx, void *data,
138 int *got_frame, AVPacket *avpkt)
140 RsccContext *ctx = avctx->priv_data;
141 GetByteContext *gbc = &ctx->gbc;
142 GetByteContext tiles_gbc;
143 AVFrame *frame = data;
144 const uint8_t *pixels, *raw;
145 uint8_t *inflated_tiles = NULL;
146 int tiles_nb, packed_size, pixel_size = 0;
149 bytestream2_init(gbc, avpkt->data, avpkt->size);
152 if (bytestream2_get_bytes_left(gbc) < 12) {
153 av_log(avctx, AV_LOG_ERROR, "Packet too small (%d)\n", avpkt->size);
154 return AVERROR_INVALIDDATA;
157 /* Read number of tiles, and allocate the array */
158 tiles_nb = bytestream2_get_le16(gbc);
159 av_fast_malloc(&ctx->tiles, &ctx->tiles_size,
160 tiles_nb * sizeof(*ctx->tiles));
162 ret = AVERROR(ENOMEM);
166 av_log(avctx, AV_LOG_DEBUG, "Frame with %d tiles.\n", tiles_nb);
168 /* When there are more than 5 tiles, they are packed together with
169 * a size header. When that size does not match the number of tiles
170 * times the tile size, it means it needs to be inflated as well */
172 uLongf packed_tiles_size;
175 packed_tiles_size = bytestream2_get_byte(gbc);
177 packed_tiles_size = bytestream2_get_le16(gbc);
179 ff_dlog(avctx, "packed tiles of size %lu.\n", packed_tiles_size);
181 /* If necessary, uncompress tiles, and hijack the bytestream reader */
182 if (packed_tiles_size != tiles_nb * TILE_SIZE) {
183 uLongf length = tiles_nb * TILE_SIZE;
184 inflated_tiles = av_malloc(length);
185 if (!inflated_tiles) {
186 ret = AVERROR(ENOMEM);
190 ret = uncompress(inflated_tiles, &length,
191 gbc->buffer, packed_tiles_size);
193 av_log(avctx, AV_LOG_ERROR, "Tile deflate error %d.\n", ret);
194 ret = AVERROR_UNKNOWN;
198 /* Skip the compressed tile section in the main byte reader,
199 * and point it to read the newly uncompressed data */
200 bytestream2_skip(gbc, packed_tiles_size);
201 bytestream2_init(&tiles_gbc, inflated_tiles, length);
206 /* Fill in array of tiles, keeping track of how many pixels are updated */
207 for (i = 0; i < tiles_nb; i++) {
208 ctx->tiles[i].x = bytestream2_get_le16(gbc);
209 ctx->tiles[i].w = bytestream2_get_le16(gbc);
210 ctx->tiles[i].y = bytestream2_get_le16(gbc);
211 ctx->tiles[i].h = bytestream2_get_le16(gbc);
213 pixel_size += ctx->tiles[i].w * ctx->tiles[i].h * ctx->component_size;
215 ff_dlog(avctx, "tile %d orig(%d,%d) %dx%d.\n", i,
216 ctx->tiles[i].x, ctx->tiles[i].y,
217 ctx->tiles[i].w, ctx->tiles[i].h);
219 if (ctx->tiles[i].w == 0 || ctx->tiles[i].h == 0) {
220 av_log(avctx, AV_LOG_ERROR,
221 "invalid tile %d at (%d.%d) with size %dx%d.\n", i,
222 ctx->tiles[i].x, ctx->tiles[i].y,
223 ctx->tiles[i].w, ctx->tiles[i].h);
224 ret = AVERROR_INVALIDDATA;
226 } else if (ctx->tiles[i].x + ctx->tiles[i].w > avctx->width ||
227 ctx->tiles[i].y + ctx->tiles[i].h > avctx->height) {
228 av_log(avctx, AV_LOG_ERROR,
229 "out of bounds tile %d at (%d.%d) with size %dx%d.\n", i,
230 ctx->tiles[i].x, ctx->tiles[i].y,
231 ctx->tiles[i].w, ctx->tiles[i].h);
232 ret = AVERROR_INVALIDDATA;
237 /* Reset the reader in case it had been modified before */
240 /* Extract how much pixel data the tiles contain */
241 if (pixel_size < 0x100)
242 packed_size = bytestream2_get_byte(gbc);
243 else if (pixel_size < 0x10000)
244 packed_size = bytestream2_get_le16(gbc);
245 else if (pixel_size < 0x1000000)
246 packed_size = bytestream2_get_le24(gbc);
248 packed_size = bytestream2_get_le32(gbc);
250 ff_dlog(avctx, "pixel_size %d packed_size %d.\n", pixel_size, packed_size);
252 /* Get pixels buffer, it may be deflated or just raw */
253 if (pixel_size == packed_size) {
254 pixels = gbc->buffer;
256 uLongf len = ctx->inflated_size;
257 ret = uncompress(ctx->inflated_buf, &len, gbc->buffer, packed_size);
259 av_log(avctx, AV_LOG_ERROR, "Pixel deflate error %d.\n", ret);
260 ret = AVERROR_UNKNOWN;
263 pixels = ctx->inflated_buf;
266 /* Allocate when needed */
267 ret = ff_reget_buffer(avctx, ctx->reference);
271 /* Pointer to actual pixels, will be updated when data is consumed */
273 for (i = 0; i < tiles_nb; i++) {
274 uint8_t *dst = ctx->reference->data[0] + ctx->reference->linesize[0] *
275 (avctx->height - ctx->tiles[i].y - 1) +
276 ctx->tiles[i].x * ctx->component_size;
277 av_image_copy_plane(dst, -1 * ctx->reference->linesize[0],
278 raw, ctx->tiles[i].w * ctx->component_size,
279 ctx->tiles[i].w * ctx->component_size,
281 raw += ctx->tiles[i].w * ctx->component_size * ctx->tiles[i].h;
284 /* Frame is ready to be output */
285 ret = av_frame_ref(frame, ctx->reference);
289 /* Keyframe when the number of pixels updated matches the whole surface */
290 if (pixel_size == ctx->inflated_size) {
291 frame->pict_type = AV_PICTURE_TYPE_I;
292 frame->key_frame = 1;
294 frame->pict_type = AV_PICTURE_TYPE_P;
297 /* Palette handling */
298 if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {
299 const uint8_t *palette = av_packet_get_side_data(avpkt,
303 frame->palette_has_changed = 1;
304 memcpy(ctx->palette, palette, AVPALETTE_SIZE);
306 memcpy(frame->data[1], ctx->palette, AVPALETTE_SIZE);
312 av_free(inflated_tiles);
316 AVCodec ff_rscc_decoder = {
318 .long_name = NULL_IF_CONFIG_SMALL("innoHeim/Rsupport Screen Capture Codec"),
319 .type = AVMEDIA_TYPE_VIDEO,
320 .id = AV_CODEC_ID_RSCC,
322 .decode = rscc_decode_frame,
324 .priv_data_size = sizeof(RsccContext),
325 .capabilities = AV_CODEC_CAP_DR1,
326 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
327 FF_CODEC_CAP_INIT_CLEANUP,