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: 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 /* zlib interaction */
63 uint8_t *inflated_buf;
67 static av_cold int rscc_init(AVCodecContext *avctx)
69 RsccContext *ctx = avctx->priv_data;
71 /* These needs to be set to estimate uncompressed buffer */
72 int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
74 av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
75 avctx->width, avctx->height);
79 /* Allocate reference frame */
80 ctx->reference = av_frame_alloc();
82 return AVERROR(ENOMEM);
84 /* Get pixel format and the size of the pixel */
85 if (avctx->codec_tag == MKTAG('I', 'S', 'C', 'C')) {
86 avctx->pix_fmt = AV_PIX_FMT_BGRA;
87 ctx->component_size = 4;
88 } else if (avctx->codec_tag == MKTAG('R', 'S', 'C', 'C')) {
89 ctx->component_size = avctx->bits_per_coded_sample / 8;
90 switch (avctx->bits_per_coded_sample) {
92 avpriv_report_missing_feature(avctx, "8 bits per pixel");
93 return AVERROR_PATCHWELCOME;
95 avctx->pix_fmt = AV_PIX_FMT_RGB555LE;
98 avctx->pix_fmt = AV_PIX_FMT_BGR24;
101 avctx->pix_fmt = AV_PIX_FMT_BGRA;
104 av_log(avctx, AV_LOG_ERROR, "Invalid bits per pixel value (%d)\n",
105 avctx->bits_per_coded_sample);
106 return AVERROR_INVALIDDATA;
109 av_log(avctx, AV_LOG_ERROR, "Invalid codec tag\n");
110 return AVERROR_INVALIDDATA;
113 /* Store the value to check for keyframes */
114 ctx->inflated_size = avctx->width * avctx->height * ctx->component_size;
116 /* Allocate maximum size possible, a full frame */
117 ctx->inflated_buf = av_malloc(ctx->inflated_size);
118 if (!ctx->inflated_buf)
119 return AVERROR(ENOMEM);
124 static av_cold int rscc_close(AVCodecContext *avctx)
126 RsccContext *ctx = avctx->priv_data;
128 av_freep(&ctx->tiles);
129 av_freep(&ctx->inflated_buf);
130 av_frame_free(&ctx->reference);
135 static int rscc_decode_frame(AVCodecContext *avctx, void *data,
136 int *got_frame, AVPacket *avpkt)
138 RsccContext *ctx = avctx->priv_data;
139 GetByteContext *gbc = &ctx->gbc;
140 GetByteContext tiles_gbc;
141 AVFrame *frame = data;
142 const uint8_t *pixels, *raw;
143 uint8_t *inflated_tiles = NULL;
144 int tiles_nb, packed_size, pixel_size = 0;
147 bytestream2_init(gbc, avpkt->data, avpkt->size);
150 if (bytestream2_get_bytes_left(gbc) < 12) {
151 av_log(avctx, AV_LOG_ERROR, "Packet too small (%d)\n", avpkt->size);
152 return AVERROR_INVALIDDATA;
155 /* Read number of tiles, and allocate the array */
156 tiles_nb = bytestream2_get_le16(gbc);
157 av_fast_malloc(&ctx->tiles, &ctx->tiles_size,
158 tiles_nb * sizeof(*ctx->tiles));
160 ret = AVERROR(ENOMEM);
164 av_log(avctx, AV_LOG_DEBUG, "Frame with %d tiles.\n", tiles_nb);
166 /* When there are more than 5 tiles, they are packed together with
167 * a size header. When that size does not match the number of tiles
168 * times the tile size, it means it needs to be inflated as well */
170 uLongf packed_tiles_size;
173 packed_tiles_size = bytestream2_get_byte(gbc);
175 packed_tiles_size = bytestream2_get_le16(gbc);
177 ff_dlog(avctx, "packed tiles of size %lu.\n", packed_tiles_size);
179 /* If necessary, uncompress tiles, and hijack the bytestream reader */
180 if (packed_tiles_size != tiles_nb * TILE_SIZE) {
181 uLongf length = tiles_nb * TILE_SIZE;
182 inflated_tiles = av_malloc(length);
183 if (!inflated_tiles) {
184 ret = AVERROR(ENOMEM);
188 ret = uncompress(inflated_tiles, &length,
189 gbc->buffer, packed_tiles_size);
191 av_log(avctx, AV_LOG_ERROR, "Tile deflate error %d.\n", ret);
192 ret = AVERROR_UNKNOWN;
196 /* Skip the compressed tile section in the main byte reader,
197 * and point it to read the newly uncompressed data */
198 bytestream2_skip(gbc, packed_tiles_size);
199 bytestream2_init(&tiles_gbc, inflated_tiles, length);
204 /* Fill in array of tiles, keeping track of how many pixels are updated */
205 for (i = 0; i < tiles_nb; i++) {
206 ctx->tiles[i].x = bytestream2_get_le16(gbc);
207 ctx->tiles[i].w = bytestream2_get_le16(gbc);
208 ctx->tiles[i].y = bytestream2_get_le16(gbc);
209 ctx->tiles[i].h = bytestream2_get_le16(gbc);
211 pixel_size += ctx->tiles[i].w * ctx->tiles[i].h * ctx->component_size;
213 ff_dlog(avctx, "tile %d orig(%d,%d) %dx%d.\n", i,
214 ctx->tiles[i].x, ctx->tiles[i].y,
215 ctx->tiles[i].w, ctx->tiles[i].h);
217 if (ctx->tiles[i].w == 0 || ctx->tiles[i].h == 0) {
218 av_log(avctx, AV_LOG_ERROR,
219 "invalid tile %d at (%d.%d) with size %dx%d.\n", i,
220 ctx->tiles[i].x, ctx->tiles[i].y,
221 ctx->tiles[i].w, ctx->tiles[i].h);
222 ret = AVERROR_INVALIDDATA;
224 } else if (ctx->tiles[i].x + ctx->tiles[i].w > avctx->width ||
225 ctx->tiles[i].y + ctx->tiles[i].h > avctx->height) {
226 av_log(avctx, AV_LOG_ERROR,
227 "out of bounds tile %d at (%d.%d) with size %dx%d.\n", i,
228 ctx->tiles[i].x, ctx->tiles[i].y,
229 ctx->tiles[i].w, ctx->tiles[i].h);
230 ret = AVERROR_INVALIDDATA;
235 /* Reset the reader in case it had been modified before */
238 /* Extract how much pixel data the tiles contain */
239 if (pixel_size < 0x100)
240 packed_size = bytestream2_get_byte(gbc);
241 else if (pixel_size < 0x10000)
242 packed_size = bytestream2_get_le16(gbc);
243 else if (pixel_size < 0x1000000)
244 packed_size = bytestream2_get_le24(gbc);
246 packed_size = bytestream2_get_le32(gbc);
248 ff_dlog(avctx, "pixel_size %d packed_size %d.\n", pixel_size, packed_size);
250 /* Get pixels buffer, it may be deflated or just raw */
251 if (pixel_size == packed_size) {
252 pixels = gbc->buffer;
254 uLongf len = ctx->inflated_size;
255 ret = uncompress(ctx->inflated_buf, &len, gbc->buffer, packed_size);
257 av_log(avctx, AV_LOG_ERROR, "Pixel deflate error %d.\n", ret);
258 ret = AVERROR_UNKNOWN;
261 pixels = ctx->inflated_buf;
264 /* Allocate when needed */
265 ret = ff_reget_buffer(avctx, ctx->reference);
269 /* Pointer to actual pixels, will be updated when data is consumed */
271 for (i = 0; i < tiles_nb; i++) {
272 uint8_t *dst = ctx->reference->data[0] + ctx->reference->linesize[0] *
273 (avctx->height - ctx->tiles[i].y - 1) +
274 ctx->tiles[i].x * ctx->component_size;
275 av_image_copy_plane(dst, -1 * ctx->reference->linesize[0],
276 raw, ctx->tiles[i].w * ctx->component_size,
277 ctx->tiles[i].w * ctx->component_size,
279 raw += ctx->tiles[i].w * ctx->component_size * ctx->tiles[i].h;
282 /* Frame is ready to be output */
283 ret = av_frame_ref(frame, ctx->reference);
287 /* Keyframe when the number of pixels updated matches the whole surface */
288 if (pixel_size == ctx->inflated_size) {
289 frame->pict_type = AV_PICTURE_TYPE_I;
290 frame->key_frame = 1;
292 frame->pict_type = AV_PICTURE_TYPE_P;
297 av_free(inflated_tiles);
301 AVCodec ff_rscc_decoder = {
303 .long_name = NULL_IF_CONFIG_SMALL("innoHeim/Rsupport Screen Capture Codec"),
304 .type = AVMEDIA_TYPE_VIDEO,
305 .id = AV_CODEC_ID_RSCC,
307 .decode = rscc_decode_frame,
309 .priv_data_size = sizeof(RsccContext),
310 .capabilities = AV_CODEC_CAP_DR1,
311 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
312 FF_CODEC_CAP_INIT_CLEANUP,