FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/rscc.c
Date: 2025-10-30 05:42:18
Exec Total Coverage
Lines: 119 177 67.2%
Functions: 3 3 100.0%
Branches: 51 83 61.4%
Line Branch Exec Source
1 /*
2 * innoHeim/Rsupport Screen Capture Codec
3 * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 /**
23 * @file
24 * innoHeim/Rsupport Screen Capture Codec decoder
25 *
26 * Fourcc: ISCC, RSCC
27 *
28 * Lossless codec, data stored in tiles, with optional deflate compression.
29 *
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.
33 *
34 * Supports: PAL8, BGRA, BGR24, RGB555
35 */
36
37 #include <stdint.h>
38 #include <string.h>
39 #include <zlib.h>
40
41 #include "libavutil/imgutils.h"
42 #include "libavutil/internal.h"
43 #include "libavutil/mem.h"
44
45 #include "avcodec.h"
46 #include "bytestream.h"
47 #include "codec_internal.h"
48 #include "decode.h"
49
50 #define TILE_SIZE 8
51
52 typedef struct Tile {
53 int x, y;
54 int w, h;
55 } Tile;
56
57 typedef struct RsccContext {
58 GetByteContext gbc;
59 AVFrame *reference;
60 Tile *tiles;
61 unsigned int tiles_size;
62 int component_size;
63
64 uint8_t palette[AVPALETTE_SIZE];
65
66 /* zlib interaction */
67 uint8_t *inflated_buf;
68 uLongf inflated_size;
69 int valid_pixels;
70 } RsccContext;
71
72 10 static av_cold int rscc_init(AVCodecContext *avctx)
73 {
74 10 RsccContext *ctx = avctx->priv_data;
75
76 /* These needs to be set to estimate uncompressed buffer */
77 10 int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
78
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 10 if (ret < 0) {
79 ✗ av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
80 avctx->width, avctx->height);
81 ✗ return ret;
82 }
83
84 /* Allocate reference frame */
85 10 ctx->reference = av_frame_alloc();
86
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 10 if (!ctx->reference)
87 ✗ return AVERROR(ENOMEM);
88
89 /* Get pixel format and the size of the pixel */
90
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 10 if (avctx->codec_tag == MKTAG('I', 'S', 'C', 'C')) {
91
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 2 if (avctx->extradata && avctx->extradata_size == 4) {
92
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 2 if ((avctx->extradata[0] >> 1) & 1) {
93 2 avctx->pix_fmt = AV_PIX_FMT_BGRA;
94 2 ctx->component_size = 4;
95 } else {
96 ✗ avctx->pix_fmt = AV_PIX_FMT_BGR24;
97 ✗ ctx->component_size = 3;
98 }
99 } else {
100 ✗ avctx->pix_fmt = AV_PIX_FMT_BGRA;
101 ✗ ctx->component_size = 4;
102 }
103
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 8 } else if (avctx->codec_tag == MKTAG('R', 'S', 'C', 'C')) {
104 8 ctx->component_size = avctx->bits_per_coded_sample / 8;
105
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 8 switch (avctx->bits_per_coded_sample) {
106 2 case 8:
107 2 avctx->pix_fmt = AV_PIX_FMT_PAL8;
108 2 break;
109 2 case 16:
110 2 avctx->pix_fmt = AV_PIX_FMT_RGB555LE;
111 2 break;
112 2 case 24:
113 2 avctx->pix_fmt = AV_PIX_FMT_BGR24;
114 2 break;
115 2 case 32:
116 2 avctx->pix_fmt = AV_PIX_FMT_BGR0;
117 2 break;
118 ✗ default:
119 ✗ av_log(avctx, AV_LOG_ERROR, "Invalid bits per pixel value (%d)\n",
120 avctx->bits_per_coded_sample);
121 ✗ return AVERROR_INVALIDDATA;
122 }
123 } else {
124 ✗ avctx->pix_fmt = AV_PIX_FMT_BGR0;
125 ✗ ctx->component_size = 4;
126 ✗ av_log(avctx, AV_LOG_WARNING, "Invalid codec tag\n");
127 }
128
129 /* Store the value to check for keyframes */
130 10 ctx->inflated_size = avctx->width * avctx->height * ctx->component_size;
131
132 /* Allocate maximum size possible, a full frame */
133 10 ctx->inflated_buf = av_malloc(ctx->inflated_size);
134
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 10 if (!ctx->inflated_buf)
135 ✗ return AVERROR(ENOMEM);
136
137 10 return 0;
138 }
139
140 10 static av_cold int rscc_close(AVCodecContext *avctx)
141 {
142 10 RsccContext *ctx = avctx->priv_data;
143
144 10 av_freep(&ctx->tiles);
145 10 av_freep(&ctx->inflated_buf);
146 10 av_frame_free(&ctx->reference);
147
148 10 return 0;
149 }
150
151 32 static int rscc_decode_frame(AVCodecContext *avctx, AVFrame *frame,
152 int *got_frame, AVPacket *avpkt)
153 {
154 32 RsccContext *ctx = avctx->priv_data;
155 32 GetByteContext *gbc = &ctx->gbc;
156 GetByteContext tiles_gbc;
157 const uint8_t *pixels, *raw;
158 32 uint8_t *inflated_tiles = NULL;
159 32 int tiles_nb, packed_size, pixel_size = 0;
160 32 int i, ret = 0;
161
162 32 bytestream2_init(gbc, avpkt->data, avpkt->size);
163
164 /* Size check */
165
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 32 if (bytestream2_get_bytes_left(gbc) < 12) {
166 ✗ av_log(avctx, AV_LOG_ERROR, "Packet too small (%d)\n", avpkt->size);
167 ✗ return AVERROR_INVALIDDATA;
168 }
169
170 /* Read number of tiles, and allocate the array */
171 32 tiles_nb = bytestream2_get_le16(gbc);
172
173
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 32 if (tiles_nb == 0) {
174 ✗ av_log(avctx, AV_LOG_DEBUG, "no tiles\n");
175 ✗ return avpkt->size;
176 }
177
178 32 av_fast_malloc(&ctx->tiles, &ctx->tiles_size,
179 tiles_nb * sizeof(*ctx->tiles));
180
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 32 if (!ctx->tiles) {
181 ✗ ret = AVERROR(ENOMEM);
182 ✗ goto end;
183 }
184
185 32 av_log(avctx, AV_LOG_DEBUG, "Frame with %d tiles.\n", tiles_nb);
186
187 /* When there are more than 5 tiles, they are packed together with
188 * a size header. When that size does not match the number of tiles
189 * times the tile size, it means it needs to be inflated as well */
190
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 32 if (tiles_nb > 5) {
191 uLongf packed_tiles_size;
192
193
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 24 if (tiles_nb < 32)
194 17 packed_tiles_size = bytestream2_get_byte(gbc);
195 else
196 7 packed_tiles_size = bytestream2_get_le16(gbc);
197
198 ff_dlog(avctx, "packed tiles of size %lu.\n", packed_tiles_size);
199
200 /* If necessary, uncompress tiles, and hijack the bytestream reader */
201
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 24 if (packed_tiles_size != tiles_nb * TILE_SIZE) {
202 24 uLongf length = tiles_nb * TILE_SIZE;
203
204
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 24 if (bytestream2_get_bytes_left(gbc) < packed_tiles_size) {
205 ✗ ret = AVERROR_INVALIDDATA;
206 ✗ goto end;
207 }
208
209 24 inflated_tiles = av_malloc(length);
210
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 24 if (!inflated_tiles) {
211 ✗ ret = AVERROR(ENOMEM);
212 ✗ goto end;
213 }
214
215 24 ret = uncompress(inflated_tiles, &length,
216 24 gbc->buffer, packed_tiles_size);
217
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 24 if (ret) {
218 ✗ av_log(avctx, AV_LOG_ERROR, "Tile deflate error %d.\n", ret);
219 ✗ ret = AVERROR_UNKNOWN;
220 ✗ goto end;
221 }
222
223 /* Skip the compressed tile section in the main byte reader,
224 * and point it to read the newly uncompressed data */
225 24 bytestream2_skip(gbc, packed_tiles_size);
226 24 bytestream2_init(&tiles_gbc, inflated_tiles, length);
227 24 gbc = &tiles_gbc;
228 }
229 }
230
231 /* Fill in array of tiles, keeping track of how many pixels are updated */
232
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 712 for (i = 0; i < tiles_nb; i++) {
233 680 ctx->tiles[i].x = bytestream2_get_le16(gbc);
234 680 ctx->tiles[i].w = bytestream2_get_le16(gbc);
235 680 ctx->tiles[i].y = bytestream2_get_le16(gbc);
236 680 ctx->tiles[i].h = bytestream2_get_le16(gbc);
237
238
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 680 if (pixel_size + ctx->tiles[i].w * (int64_t)ctx->tiles[i].h * ctx->component_size > INT_MAX) {
239 ✗ av_log(avctx, AV_LOG_ERROR, "Invalid tile dimensions\n");
240 ✗ ret = AVERROR_INVALIDDATA;
241 ✗ goto end;
242 }
243
244 680 pixel_size += ctx->tiles[i].w * ctx->tiles[i].h * ctx->component_size;
245
246 ff_dlog(avctx, "tile %d orig(%d,%d) %dx%d.\n", i,
247 ctx->tiles[i].x, ctx->tiles[i].y,
248 ctx->tiles[i].w, ctx->tiles[i].h);
249
250
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 680 if (ctx->tiles[i].w == 0 || ctx->tiles[i].h == 0) {
251 ✗ av_log(avctx, AV_LOG_ERROR,
252 "invalid tile %d at (%d.%d) with size %dx%d.\n", i,
253 ✗ ctx->tiles[i].x, ctx->tiles[i].y,
254 ✗ ctx->tiles[i].w, ctx->tiles[i].h);
255 ✗ ret = AVERROR_INVALIDDATA;
256 ✗ goto end;
257
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 680 } else if (ctx->tiles[i].x + ctx->tiles[i].w > avctx->width ||
258
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 680 ctx->tiles[i].y + ctx->tiles[i].h > avctx->height) {
259 ✗ av_log(avctx, AV_LOG_ERROR,
260 "out of bounds tile %d at (%d.%d) with size %dx%d.\n", i,
261 ✗ ctx->tiles[i].x, ctx->tiles[i].y,
262 ✗ ctx->tiles[i].w, ctx->tiles[i].h);
263 ✗ ret = AVERROR_INVALIDDATA;
264 ✗ goto end;
265 }
266 }
267
268 /* Reset the reader in case it had been modified before */
269 32 gbc = &ctx->gbc;
270
271 /* Extract how much pixel data the tiles contain */
272
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 32 if (pixel_size < 0x100)
273 ✗ packed_size = bytestream2_get_byte(gbc);
274
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 32 else if (pixel_size < 0x10000)
275 ✗ packed_size = bytestream2_get_le16(gbc);
276
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 32 else if (pixel_size < 0x1000000)
277 32 packed_size = bytestream2_get_le24(gbc);
278 else
279 ✗ packed_size = bytestream2_get_le32(gbc);
280
281 ff_dlog(avctx, "pixel_size %d packed_size %d.\n", pixel_size, packed_size);
282
283
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 32 if (packed_size < 0) {
284 ✗ av_log(avctx, AV_LOG_ERROR, "Invalid tile size %d\n", packed_size);
285 ✗ ret = AVERROR_INVALIDDATA;
286 ✗ goto end;
287 }
288
289 /* Get pixels buffer, it may be deflated or just raw */
290
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 32 if (pixel_size == packed_size) {
291 ✗ if (bytestream2_get_bytes_left(gbc) < pixel_size) {
292 ✗ av_log(avctx, AV_LOG_ERROR, "Insufficient input for %d\n", pixel_size);
293 ✗ ret = AVERROR_INVALIDDATA;
294 ✗ goto end;
295 }
296 ✗ pixels = gbc->buffer;
297 } else {
298 32 uLongf len = ctx->inflated_size;
299
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 32 if (bytestream2_get_bytes_left(gbc) < packed_size) {
300 2 av_log(avctx, AV_LOG_ERROR, "Insufficient input for %d\n", packed_size);
301 2 ret = AVERROR_INVALIDDATA;
302 2 goto end;
303 }
304
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 30 if (ctx->inflated_size < pixel_size) {
305 ✗ ret = AVERROR_INVALIDDATA;
306 ✗ goto end;
307 }
308 30 ret = uncompress(ctx->inflated_buf, &len, gbc->buffer, packed_size);
309
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 30 if (ret) {
310 ✗ av_log(avctx, AV_LOG_ERROR, "Pixel deflate error %d.\n", ret);
311 ✗ ret = AVERROR_UNKNOWN;
312 ✗ goto end;
313 }
314 30 pixels = ctx->inflated_buf;
315 }
316
317 /* Allocate when needed */
318 30 ret = ff_reget_buffer(avctx, ctx->reference, 0);
319
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 30 if (ret < 0)
320 ✗ goto end;
321
322 /* Pointer to actual pixels, will be updated when data is consumed */
323 30 raw = pixels;
324
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 694 for (i = 0; i < tiles_nb; i++) {
325 664 uint8_t *dst = ctx->reference->data[0] + ctx->reference->linesize[0] *
326 664 (avctx->height - ctx->tiles[i].y - 1) +
327 664 ctx->tiles[i].x * ctx->component_size;
328 664 av_image_copy_plane(dst, -1 * ctx->reference->linesize[0],
329 664 raw, ctx->tiles[i].w * ctx->component_size,
330 664 ctx->tiles[i].w * ctx->component_size,
331 664 ctx->tiles[i].h);
332 664 raw += ctx->tiles[i].w * ctx->component_size * ctx->tiles[i].h;
333 }
334
335 /* Frame is ready to be output */
336 30 ret = av_frame_ref(frame, ctx->reference);
337
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 30 if (ret < 0)
338 ✗ goto end;
339
340 /* Keyframe when the number of pixels updated matches the whole surface */
341
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 30 if (pixel_size == ctx->inflated_size) {
342 5 frame->pict_type = AV_PICTURE_TYPE_I;
343 5 frame->flags |= AV_FRAME_FLAG_KEY;
344 } else {
345 25 frame->pict_type = AV_PICTURE_TYPE_P;
346 }
347
348 /* Palette handling */
349
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 30 if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {
350 1 ff_copy_palette(ctx->palette, avpkt, avctx);
351 1 memcpy(frame->data[1], ctx->palette, AVPALETTE_SIZE);
352 }
353 // We only return a picture when enough of it is undamaged, this avoids copying nearly broken frames around
354
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 30 if (ctx->valid_pixels < ctx->inflated_size)
355 5 ctx->valid_pixels += pixel_size;
356
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 30 if (ctx->valid_pixels >= ctx->inflated_size * (100 - avctx->discard_damaged_percentage) / 100)
357 30 *got_frame = 1;
358
359 30 ret = avpkt->size;
360 32 end:
361 32 av_free(inflated_tiles);
362 32 return ret;
363 }
364
365 const FFCodec ff_rscc_decoder = {
366 .p.name = "rscc",
367 CODEC_LONG_NAME("innoHeim/Rsupport Screen Capture Codec"),
368 .p.type = AVMEDIA_TYPE_VIDEO,
369 .p.id = AV_CODEC_ID_RSCC,
370 .init = rscc_init,
371 FF_CODEC_DECODE_CB(rscc_decode_frame),
372 .close = rscc_close,
373 .priv_data_size = sizeof(RsccContext),
374 .p.capabilities = AV_CODEC_CAP_DR1,
375 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
376 };
377