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 if (avctx->codec_tag == MKTAG('I','S','C','C')) {
84 avctx->pix_fmt = AV_PIX_FMT_BGRA;
86 avctx->pix_fmt = AV_PIX_FMT_BGR0;
89 /* Store the value to check for keyframes */
90 ctx->inflated_size = avctx->width * avctx->height * 4;
92 /* Allocate maximum size possible, a full frame */
93 ctx->inflated_buf = av_malloc(ctx->inflated_size);
94 if (!ctx->inflated_buf)
95 return AVERROR(ENOMEM);
100 static av_cold int rscc_close(AVCodecContext *avctx)
102 RsccContext *ctx = avctx->priv_data;
104 av_freep(&ctx->tiles);
105 av_freep(&ctx->inflated_buf);
106 av_frame_free(&ctx->reference);
111 static int rscc_decode_frame(AVCodecContext *avctx, void *data,
112 int *got_frame, AVPacket *avpkt)
114 RsccContext *ctx = avctx->priv_data;
115 GetByteContext *gbc = &ctx->gbc;
116 GetByteContext tiles_gbc;
117 AVFrame *frame = data;
118 const uint8_t *pixels, *raw;
119 uint8_t *inflated_tiles = NULL;
120 int tiles_nb, packed_size, pixel_size = 0;
123 bytestream2_init(gbc, avpkt->data, avpkt->size);
126 if (bytestream2_get_bytes_left(gbc) < 12) {
127 av_log(avctx, AV_LOG_ERROR, "Packet too small (%d)\n", avpkt->size);
128 return AVERROR_INVALIDDATA;
131 /* Read number of tiles, and allocate the array */
132 tiles_nb = bytestream2_get_le16(gbc);
133 av_fast_malloc(&ctx->tiles, &ctx->tiles_size,
134 tiles_nb * sizeof(*ctx->tiles));
136 ret = AVERROR(ENOMEM);
140 av_log(avctx, AV_LOG_DEBUG, "Frame with %d tiles.\n", tiles_nb);
142 /* When there are more than 5 tiles, they are packed together with
143 * a size header. When that size does not match the number of tiles
144 * times the tile size, it means it needs to be inflated as well */
146 uLongf packed_tiles_size;
149 packed_tiles_size = bytestream2_get_byte(gbc);
151 packed_tiles_size = bytestream2_get_le16(gbc);
153 ff_dlog(avctx, "packed tiles of size %lu.\n", packed_tiles_size);
155 /* If necessary, uncompress tiles, and hijack the bytestream reader */
156 if (packed_tiles_size != tiles_nb * TILE_SIZE) {
157 uLongf length = tiles_nb * TILE_SIZE;
158 inflated_tiles = av_malloc(length);
159 if (!inflated_tiles) {
160 ret = AVERROR(ENOMEM);
164 ret = uncompress(inflated_tiles, &length,
165 gbc->buffer, packed_tiles_size);
167 av_log(avctx, AV_LOG_ERROR, "Tile deflate error %d.\n", ret);
168 ret = AVERROR_UNKNOWN;
172 /* Skip the compressed tile section in the main byte reader,
173 * and point it to read the newly uncompressed data */
174 bytestream2_skip(gbc, packed_tiles_size);
175 bytestream2_init(&tiles_gbc, inflated_tiles, length);
180 /* Fill in array of tiles, keeping track of how many pixels are updated */
181 for (i = 0; i < tiles_nb; i++) {
182 ctx->tiles[i].x = bytestream2_get_le16(gbc);
183 ctx->tiles[i].w = bytestream2_get_le16(gbc);
184 ctx->tiles[i].y = bytestream2_get_le16(gbc);
185 ctx->tiles[i].h = bytestream2_get_le16(gbc);
187 pixel_size += ctx->tiles[i].w * ctx->tiles[i].h * 4;
189 ff_dlog(avctx, "tile %d orig(%d,%d) %dx%d.\n", i,
190 ctx->tiles[i].x, ctx->tiles[i].y,
191 ctx->tiles[i].w, ctx->tiles[i].h);
193 if (ctx->tiles[i].w == 0 || ctx->tiles[i].h == 0) {
194 av_log(avctx, AV_LOG_ERROR,
195 "invalid tile %d at (%d.%d) with size %dx%d.\n", i,
196 ctx->tiles[i].x, ctx->tiles[i].y,
197 ctx->tiles[i].w, ctx->tiles[i].h);
198 ret = AVERROR_INVALIDDATA;
200 } else if (ctx->tiles[i].x + ctx->tiles[i].w > avctx->width ||
201 ctx->tiles[i].y + ctx->tiles[i].h > avctx->height) {
202 av_log(avctx, AV_LOG_ERROR,
203 "out of bounds tile %d at (%d.%d) with size %dx%d.\n", i,
204 ctx->tiles[i].x, ctx->tiles[i].y,
205 ctx->tiles[i].w, ctx->tiles[i].h);
206 ret = AVERROR_INVALIDDATA;
211 /* Reset the reader in case it had been modified before */
214 /* Extract how much pixel data the tiles contain */
215 if (pixel_size < 0x100)
216 packed_size = bytestream2_get_byte(gbc);
217 else if (pixel_size < 0x10000)
218 packed_size = bytestream2_get_le16(gbc);
219 else if (pixel_size < 0x1000000)
220 packed_size = bytestream2_get_le24(gbc);
222 packed_size = bytestream2_get_le32(gbc);
224 ff_dlog(avctx, "pixel_size %d packed_size %d.\n", pixel_size, packed_size);
226 /* Get pixels buffer, it may be deflated or just raw */
227 if (pixel_size == packed_size) {
228 if (bytestream2_get_bytes_left(gbc) < pixel_size) {
229 av_log(avctx, AV_LOG_ERROR, "Insufficient input for %d\n", pixel_size);
230 ret = AVERROR_INVALIDDATA;
233 pixels = gbc->buffer;
235 uLongf len = ctx->inflated_size;
236 ret = uncompress(ctx->inflated_buf, &len, gbc->buffer, packed_size);
238 av_log(avctx, AV_LOG_ERROR, "Pixel deflate error %d.\n", ret);
239 ret = AVERROR_UNKNOWN;
242 pixels = ctx->inflated_buf;
245 /* Allocate when needed */
246 ret = ff_reget_buffer(avctx, ctx->reference);
250 /* Pointer to actual pixels, will be updated when data is consumed */
252 for (i = 0; i < tiles_nb; i++) {
253 uint8_t *dst = ctx->reference->data[0] + ctx->reference->linesize[0] *
254 (avctx->height - ctx->tiles[i].y - 1) +
256 av_image_copy_plane(dst, -1 * ctx->reference->linesize[0],
257 raw, ctx->tiles[i].w * 4,
258 ctx->tiles[i].w * 4, ctx->tiles[i].h);
259 raw += ctx->tiles[i].w * 4 * ctx->tiles[i].h;
262 /* Frame is ready to be output */
263 ret = av_frame_ref(frame, ctx->reference);
267 /* Keyframe when the number of pixels updated matches the whole surface */
268 if (pixel_size == ctx->inflated_size) {
269 frame->pict_type = AV_PICTURE_TYPE_I;
270 frame->key_frame = 1;
272 frame->pict_type = AV_PICTURE_TYPE_P;
277 av_free(inflated_tiles);
281 AVCodec ff_rscc_decoder = {
283 .long_name = NULL_IF_CONFIG_SMALL("innoHeim/Rsupport Screen Capture Codec"),
284 .type = AVMEDIA_TYPE_VIDEO,
285 .id = AV_CODEC_ID_RSCC,
287 .decode = rscc_decode_frame,
289 .priv_data_size = sizeof(RsccContext),
290 .capabilities = AV_CODEC_CAP_DR1,
291 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
292 FF_CODEC_CAP_INIT_CLEANUP,