aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/rscc.c
blob: 0ec54ac1b05815408cdcf75d4b3ce314ca81fa55 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
/*
 * innoHeim/Rsupport Screen Capture Codec
 * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * innoHeim/Rsupport Screen Capture Codec decoder
 *
 * Fourcc: ISCC, RSCC
 *
 * Lossless codec, data stored in tiles, with optional deflate compression.
 *
 * Header contains the number of tiles in a frame with the tile coordinates,
 * and it can be deflated or not. Similarly, pixel data comes after the header
 * and a variable size value, and it can be deflated or just raw.
 *
 * Supports: PAL8, BGRA, BGR24, RGB555
 */

#include <stdint.h>
#include <string.h>
#include <zlib.h>

#include "libavutil/imgutils.h"
#include "libavutil/internal.h"

#include "avcodec.h"
#include "bytestream.h"
#include "decode.h"
#include "internal.h"

#define TILE_SIZE 8

typedef struct Tile {
    int x, y;
    int w, h;
} Tile;

typedef struct RsccContext {
    GetByteContext gbc;
    AVFrame *reference;
    Tile *tiles;
    unsigned int tiles_size;
    int component_size;

    uint8_t palette[AVPALETTE_SIZE];

    /* zlib interaction */
    uint8_t *inflated_buf;
    uLongf inflated_size;
    int valid_pixels;
} RsccContext;

static av_cold int rscc_init(AVCodecContext *avctx)
{
    RsccContext *ctx = avctx->priv_data;

    /* These needs to be set to estimate uncompressed buffer */
    int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
    if (ret < 0) {
        av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
               avctx->width, avctx->height);
        return ret;
    }

    /* Allocate reference frame */
    ctx->reference = av_frame_alloc();
    if (!ctx->reference)
        return AVERROR(ENOMEM);

    /* Get pixel format and the size of the pixel */
    if (avctx->codec_tag == MKTAG('I', 'S', 'C', 'C')) {
        if (avctx->extradata && avctx->extradata_size == 4) {
            if ((avctx->extradata[0] >> 1) & 1) {
                avctx->pix_fmt = AV_PIX_FMT_BGRA;
                ctx->component_size = 4;
            } else {
                avctx->pix_fmt = AV_PIX_FMT_BGR24;
                ctx->component_size = 3;
            }
        } else {
            avctx->pix_fmt = AV_PIX_FMT_BGRA;
            ctx->component_size = 4;
        }
    } else if (avctx->codec_tag == MKTAG('R', 'S', 'C', 'C')) {
        ctx->component_size = avctx->bits_per_coded_sample / 8;
        switch (avctx->bits_per_coded_sample) {
        case 8:
            avctx->pix_fmt = AV_PIX_FMT_PAL8;
            break;
        case 16:
            avctx->pix_fmt = AV_PIX_FMT_RGB555LE;
            break;
        case 24:
            avctx->pix_fmt = AV_PIX_FMT_BGR24;
            break;
        case 32:
            avctx->pix_fmt = AV_PIX_FMT_BGR0;
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "Invalid bits per pixel value (%d)\n",
                   avctx->bits_per_coded_sample);
            return AVERROR_INVALIDDATA;
        }
    } else {
        avctx->pix_fmt = AV_PIX_FMT_BGR0;
        ctx->component_size = 4;
        av_log(avctx, AV_LOG_WARNING, "Invalid codec tag\n");
    }

    /* Store the value to check for keyframes */
    ctx->inflated_size = avctx->width * avctx->height * ctx->component_size;

    /* Allocate maximum size possible, a full frame */
    ctx->inflated_buf = av_malloc(ctx->inflated_size);
    if (!ctx->inflated_buf)
        return AVERROR(ENOMEM);

    return 0;
}

static av_cold int rscc_close(AVCodecContext *avctx)
{
    RsccContext *ctx = avctx->priv_data;

    av_freep(&ctx->tiles);
    av_freep(&ctx->inflated_buf);
    av_frame_free(&ctx->reference);

    return 0;
}

static int rscc_decode_frame(AVCodecContext *avctx, void *data,
                                     int *got_frame, AVPacket *avpkt)
{
    RsccContext *ctx = avctx->priv_data;
    GetByteContext *gbc = &ctx->gbc;
    GetByteContext tiles_gbc;
    AVFrame *frame = data;
    const uint8_t *pixels, *raw;
    uint8_t *inflated_tiles = NULL;
    int tiles_nb, packed_size, pixel_size = 0;
    int i, ret = 0;

    bytestream2_init(gbc, avpkt->data, avpkt->size);

    /* Size check */
    if (bytestream2_get_bytes_left(gbc) < 12) {
        av_log(avctx, AV_LOG_ERROR, "Packet too small (%d)\n", avpkt->size);
        return AVERROR_INVALIDDATA;
    }

    /* Read number of tiles, and allocate the array */
    tiles_nb = bytestream2_get_le16(gbc);

    if (tiles_nb == 0) {
        av_log(avctx, AV_LOG_DEBUG, "no tiles\n");
        return avpkt->size;
    }

    av_fast_malloc(&ctx->tiles, &ctx->tiles_size,
                   tiles_nb * sizeof(*ctx->tiles));
    if (!ctx->tiles) {
        ret = AVERROR(ENOMEM);
        goto end;
    }

    av_log(avctx, AV_LOG_DEBUG, "Frame with %d tiles.\n", tiles_nb);

    /* When there are more than 5 tiles, they are packed together with
     * a size header. When that size does not match the number of tiles
     * times the tile size, it means it needs to be inflated as well */
    if (tiles_nb > 5) {
        uLongf packed_tiles_size;

        if (tiles_nb < 32)
            packed_tiles_size = bytestream2_get_byte(gbc);
        else
            packed_tiles_size = bytestream2_get_le16(gbc);

        ff_dlog(avctx, "packed tiles of size %lu.\n", packed_tiles_size);

        /* If necessary, uncompress tiles, and hijack the bytestream reader */
        if (packed_tiles_size != tiles_nb * TILE_SIZE) {
            uLongf length = tiles_nb * TILE_SIZE;

            if (bytestream2_get_bytes_left(gbc) < packed_tiles_size) {
                ret = AVERROR_INVALIDDATA;
                goto end;
            }

            inflated_tiles = av_malloc(length);
            if (!inflated_tiles) {
                ret = AVERROR(ENOMEM);
                goto end;
            }

            ret = uncompress(inflated_tiles, &length,
                             gbc->buffer, packed_tiles_size);
            if (ret) {
                av_log(avctx, AV_LOG_ERROR, "Tile deflate error %d.\n", ret);
                ret = AVERROR_UNKNOWN;
                goto end;
            }

            /* Skip the compressed tile section in the main byte reader,
             * and point it to read the newly uncompressed data */
            bytestream2_skip(gbc, packed_tiles_size);
            bytestream2_init(&tiles_gbc, inflated_tiles, length);
            gbc = &tiles_gbc;
        }
    }

    /* Fill in array of tiles, keeping track of how many pixels are updated */
    for (i = 0; i < tiles_nb; i++) {
        ctx->tiles[i].x = bytestream2_get_le16(gbc);
        ctx->tiles[i].w = bytestream2_get_le16(gbc);
        ctx->tiles[i].y = bytestream2_get_le16(gbc);
        ctx->tiles[i].h = bytestream2_get_le16(gbc);

        if (pixel_size + ctx->tiles[i].w * (int64_t)ctx->tiles[i].h * ctx->component_size > INT_MAX) {
            av_log(avctx, AV_LOG_ERROR, "Invalid tile dimensions\n");
            ret = AVERROR_INVALIDDATA;
            goto end;
        }

        pixel_size += ctx->tiles[i].w * ctx->tiles[i].h * ctx->component_size;

        ff_dlog(avctx, "tile %d orig(%d,%d) %dx%d.\n", i,
                ctx->tiles[i].x, ctx->tiles[i].y,
                ctx->tiles[i].w, ctx->tiles[i].h);

        if (ctx->tiles[i].w == 0 || ctx->tiles[i].h == 0) {
            av_log(avctx, AV_LOG_ERROR,
                   "invalid tile %d at (%d.%d) with size %dx%d.\n", i,
                   ctx->tiles[i].x, ctx->tiles[i].y,
                   ctx->tiles[i].w, ctx->tiles[i].h);
            ret = AVERROR_INVALIDDATA;
            goto end;
        } else if (ctx->tiles[i].x + ctx->tiles[i].w > avctx->width ||
                   ctx->tiles[i].y + ctx->tiles[i].h > avctx->height) {
            av_log(avctx, AV_LOG_ERROR,
                   "out of bounds tile %d at (%d.%d) with size %dx%d.\n", i,
                   ctx->tiles[i].x, ctx->tiles[i].y,
                   ctx->tiles[i].w, ctx->tiles[i].h);
            ret = AVERROR_INVALIDDATA;
            goto end;
        }
    }

    /* Reset the reader in case it had been modified before */
    gbc = &ctx->gbc;

    /* Extract how much pixel data the tiles contain */
    if (pixel_size < 0x100)
        packed_size = bytestream2_get_byte(gbc);
    else if (pixel_size < 0x10000)
        packed_size = bytestream2_get_le16(gbc);
    else if (pixel_size < 0x1000000)
        packed_size = bytestream2_get_le24(gbc);
    else
        packed_size = bytestream2_get_le32(gbc);

    ff_dlog(avctx, "pixel_size %d packed_size %d.\n", pixel_size, packed_size);

    if (packed_size < 0) {
        av_log(avctx, AV_LOG_ERROR, "Invalid tile size %d\n", packed_size);
        ret = AVERROR_INVALIDDATA;
        goto end;
    }

    /* Get pixels buffer, it may be deflated or just raw */
    if (pixel_size == packed_size) {
        if (bytestream2_get_bytes_left(gbc) < pixel_size) {
            av_log(avctx, AV_LOG_ERROR, "Insufficient input for %d\n", pixel_size);
            ret = AVERROR_INVALIDDATA;
            goto end;
        }
        pixels = gbc->buffer;
    } else {
        uLongf len = ctx->inflated_size;
        if (bytestream2_get_bytes_left(gbc) < packed_size) {
            av_log(avctx, AV_LOG_ERROR, "Insufficient input for %d\n", packed_size);
            ret = AVERROR_INVALIDDATA;
            goto end;
        }
        if (ctx->inflated_size < pixel_size) {
            ret = AVERROR_INVALIDDATA;
            goto end;
        }
        ret = uncompress(ctx->inflated_buf, &len, gbc->buffer, packed_size);
        if (ret) {
            av_log(avctx, AV_LOG_ERROR, "Pixel deflate error %d.\n", ret);
            ret = AVERROR_UNKNOWN;
            goto end;
        }
        pixels = ctx->inflated_buf;
    }

    /* Allocate when needed */
    ret = ff_reget_buffer(avctx, ctx->reference, 0);
    if (ret < 0)
        goto end;

    /* Pointer to actual pixels, will be updated when data is consumed */
    raw = pixels;
    for (i = 0; i < tiles_nb; i++) {
        uint8_t *dst = ctx->reference->data[0] + ctx->reference->linesize[0] *
                       (avctx->height - ctx->tiles[i].y - 1) +
                       ctx->tiles[i].x * ctx->component_size;
        av_image_copy_plane(dst, -1 * ctx->reference->linesize[0],
                            raw, ctx->tiles[i].w * ctx->component_size,
                            ctx->tiles[i].w * ctx->component_size,
                            ctx->tiles[i].h);
        raw += ctx->tiles[i].w * ctx->component_size * ctx->tiles[i].h;
    }

    /* Frame is ready to be output */
    ret = av_frame_ref(frame, ctx->reference);
    if (ret < 0)
        goto end;

    /* Keyframe when the number of pixels updated matches the whole surface */
    if (pixel_size == ctx->inflated_size) {
        frame->pict_type = AV_PICTURE_TYPE_I;
        frame->key_frame = 1;
    } else {
        frame->pict_type = AV_PICTURE_TYPE_P;
    }

    /* Palette handling */
    if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {
        frame->palette_has_changed = ff_copy_palette(ctx->palette, avpkt, avctx);
        memcpy(frame->data[1], ctx->palette, AVPALETTE_SIZE);
    }
    // We only return a picture when enough of it is undamaged, this avoids copying nearly broken frames around
    if (ctx->valid_pixels < ctx->inflated_size)
        ctx->valid_pixels += pixel_size;
    if (ctx->valid_pixels >= ctx->inflated_size * (100 - avctx->discard_damaged_percentage) / 100)
        *got_frame = 1;

    ret = avpkt->size;
end:
    av_free(inflated_tiles);
    return ret;
}

const AVCodec ff_rscc_decoder = {
    .name           = "rscc",
    .long_name      = NULL_IF_CONFIG_SMALL("innoHeim/Rsupport Screen Capture Codec"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_RSCC,
    .init           = rscc_init,
    .decode         = rscc_decode_frame,
    .close          = rscc_close,
    .priv_data_size = sizeof(RsccContext),
    .capabilities   = AV_CODEC_CAP_DR1,
    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
                      FF_CODEC_CAP_INIT_CLEANUP,
};