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1 /*
2  * DirectDraw Surface image decoder
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  * DDS decoder
25  *
26  * https://msdn.microsoft.com/en-us/library/bb943982%28v=vs.85%29.aspx
27  */
28 
29 #include <stdint.h>
30 
31 #include "libavutil/libm.h"
32 #include "libavutil/imgutils.h"
33 
34 #include "avcodec.h"
35 #include "bytestream.h"
36 #include "internal.h"
37 #include "texturedsp.h"
38 #include "thread.h"
39 
40 #define DDPF_FOURCC    (1 <<  2)
41 #define DDPF_PALETTE   (1 <<  5)
42 #define DDPF_NORMALMAP (1U << 31)
43 
44 enum DDSPostProc {
45     DDS_NONE = 0,
46     DDS_ALPHA_EXP,
47     DDS_NORMAL_MAP,
48     DDS_RAW_YCOCG,
49     DDS_SWAP_ALPHA,
50     DDS_SWIZZLE_A2XY,
51     DDS_SWIZZLE_RBXG,
52     DDS_SWIZZLE_RGXB,
53     DDS_SWIZZLE_RXBG,
54     DDS_SWIZZLE_RXGB,
55     DDS_SWIZZLE_XGBR,
56     DDS_SWIZZLE_XRBG,
57     DDS_SWIZZLE_XGXR,
58 };
59 
60 enum DDSDXGIFormat {
61     DXGI_FORMAT_R16G16B16A16_TYPELESS       =  9,
62     DXGI_FORMAT_R16G16B16A16_FLOAT          = 10,
63     DXGI_FORMAT_R16G16B16A16_UNORM          = 11,
64     DXGI_FORMAT_R16G16B16A16_UINT           = 12,
65     DXGI_FORMAT_R16G16B16A16_SNORM          = 13,
66     DXGI_FORMAT_R16G16B16A16_SINT           = 14,
67 
68     DXGI_FORMAT_R8G8B8A8_TYPELESS           = 27,
69     DXGI_FORMAT_R8G8B8A8_UNORM              = 28,
70     DXGI_FORMAT_R8G8B8A8_UNORM_SRGB         = 29,
71     DXGI_FORMAT_R8G8B8A8_UINT               = 30,
72     DXGI_FORMAT_R8G8B8A8_SNORM              = 31,
73     DXGI_FORMAT_R8G8B8A8_SINT               = 32,
74 
75     DXGI_FORMAT_BC1_TYPELESS                = 70,
76     DXGI_FORMAT_BC1_UNORM                   = 71,
77     DXGI_FORMAT_BC1_UNORM_SRGB              = 72,
78     DXGI_FORMAT_BC2_TYPELESS                = 73,
79     DXGI_FORMAT_BC2_UNORM                   = 74,
80     DXGI_FORMAT_BC2_UNORM_SRGB              = 75,
81     DXGI_FORMAT_BC3_TYPELESS                = 76,
82     DXGI_FORMAT_BC3_UNORM                   = 77,
83     DXGI_FORMAT_BC3_UNORM_SRGB              = 78,
84     DXGI_FORMAT_BC4_TYPELESS                = 79,
85     DXGI_FORMAT_BC4_UNORM                   = 80,
86     DXGI_FORMAT_BC4_SNORM                   = 81,
87     DXGI_FORMAT_BC5_TYPELESS                = 82,
88     DXGI_FORMAT_BC5_UNORM                   = 83,
89     DXGI_FORMAT_BC5_SNORM                   = 84,
90     DXGI_FORMAT_B5G6R5_UNORM                = 85,
91     DXGI_FORMAT_B8G8R8A8_UNORM              = 87,
92     DXGI_FORMAT_B8G8R8X8_UNORM              = 88,
93     DXGI_FORMAT_B8G8R8A8_TYPELESS           = 90,
94     DXGI_FORMAT_B8G8R8A8_UNORM_SRGB         = 91,
95     DXGI_FORMAT_B8G8R8X8_TYPELESS           = 92,
96     DXGI_FORMAT_B8G8R8X8_UNORM_SRGB         = 93,
97 };
98 
99 typedef struct DDSContext {
100     TextureDSPContext texdsp;
101     GetByteContext gbc;
102 
103     int compressed;
104     int paletted;
105     int bpp;
106     enum DDSPostProc postproc;
107 
108     const uint8_t *tex_data; // Compressed texture
109     int tex_ratio;           // Compression ratio
110     int slice_count;         // Number of slices for threaded operations
111 
112     /* Pointer to the selected compress or decompress function. */
113     int (*tex_funct)(uint8_t *dst, ptrdiff_t stride, const uint8_t *block);
114 } DDSContext;
115 
parse_pixel_format(AVCodecContext * avctx)116 static int parse_pixel_format(AVCodecContext *avctx)
117 {
118     DDSContext *ctx = avctx->priv_data;
119     GetByteContext *gbc = &ctx->gbc;
120     uint32_t flags, fourcc, gimp_tag;
121     enum DDSDXGIFormat dxgi;
122     int size, bpp, r, g, b, a;
123     int alpha_exponent, ycocg_classic, ycocg_scaled, normal_map, array;
124 
125     /* Alternative DDS implementations use reserved1 as custom header. */
126     bytestream2_skip(gbc, 4 * 3);
127     gimp_tag = bytestream2_get_le32(gbc);
128     alpha_exponent = gimp_tag == MKTAG('A', 'E', 'X', 'P');
129     ycocg_classic  = gimp_tag == MKTAG('Y', 'C', 'G', '1');
130     ycocg_scaled   = gimp_tag == MKTAG('Y', 'C', 'G', '2');
131     bytestream2_skip(gbc, 4 * 7);
132 
133     /* Now the real DDPF starts. */
134     size = bytestream2_get_le32(gbc);
135     if (size != 32) {
136         av_log(avctx, AV_LOG_ERROR, "Invalid pixel format header %d.\n", size);
137         return AVERROR_INVALIDDATA;
138     }
139     flags = bytestream2_get_le32(gbc);
140     ctx->compressed = flags & DDPF_FOURCC;
141     ctx->paletted   = flags & DDPF_PALETTE;
142     normal_map      = flags & DDPF_NORMALMAP;
143     fourcc = bytestream2_get_le32(gbc);
144 
145     if (ctx->compressed && ctx->paletted) {
146         av_log(avctx, AV_LOG_WARNING,
147                "Disabling invalid palette flag for compressed dds.\n");
148         ctx->paletted = 0;
149     }
150 
151     bpp = ctx->bpp = bytestream2_get_le32(gbc); // rgbbitcount
152     r   = bytestream2_get_le32(gbc); // rbitmask
153     g   = bytestream2_get_le32(gbc); // gbitmask
154     b   = bytestream2_get_le32(gbc); // bbitmask
155     a   = bytestream2_get_le32(gbc); // abitmask
156 
157     bytestream2_skip(gbc, 4); // caps
158     bytestream2_skip(gbc, 4); // caps2
159     bytestream2_skip(gbc, 4); // caps3
160     bytestream2_skip(gbc, 4); // caps4
161     bytestream2_skip(gbc, 4); // reserved2
162 
163     av_log(avctx, AV_LOG_VERBOSE, "fourcc %s bpp %d "
164            "r 0x%x g 0x%x b 0x%x a 0x%x\n", av_fourcc2str(fourcc), bpp, r, g, b, a);
165     if (gimp_tag)
166         av_log(avctx, AV_LOG_VERBOSE, "and GIMP-DDS tag %s\n", av_fourcc2str(gimp_tag));
167 
168     if (ctx->compressed)
169         avctx->pix_fmt = AV_PIX_FMT_RGBA;
170 
171     if (ctx->compressed) {
172         switch (fourcc) {
173         case MKTAG('D', 'X', 'T', '1'):
174             ctx->tex_ratio = 8;
175             ctx->tex_funct = ctx->texdsp.dxt1a_block;
176             break;
177         case MKTAG('D', 'X', 'T', '2'):
178             ctx->tex_ratio = 16;
179             ctx->tex_funct = ctx->texdsp.dxt2_block;
180             break;
181         case MKTAG('D', 'X', 'T', '3'):
182             ctx->tex_ratio = 16;
183             ctx->tex_funct = ctx->texdsp.dxt3_block;
184             break;
185         case MKTAG('D', 'X', 'T', '4'):
186             ctx->tex_ratio = 16;
187             ctx->tex_funct = ctx->texdsp.dxt4_block;
188             break;
189         case MKTAG('D', 'X', 'T', '5'):
190             ctx->tex_ratio = 16;
191             if (ycocg_scaled)
192                 ctx->tex_funct = ctx->texdsp.dxt5ys_block;
193             else if (ycocg_classic)
194                 ctx->tex_funct = ctx->texdsp.dxt5y_block;
195             else
196                 ctx->tex_funct = ctx->texdsp.dxt5_block;
197             break;
198         case MKTAG('R', 'X', 'G', 'B'):
199             ctx->tex_ratio = 16;
200             ctx->tex_funct = ctx->texdsp.dxt5_block;
201             /* This format may be considered as a normal map,
202              * but it is handled differently in a separate postproc. */
203             ctx->postproc = DDS_SWIZZLE_RXGB;
204             normal_map = 0;
205             break;
206         case MKTAG('A', 'T', 'I', '1'):
207         case MKTAG('B', 'C', '4', 'U'):
208             ctx->tex_ratio = 8;
209             ctx->tex_funct = ctx->texdsp.rgtc1u_block;
210             break;
211         case MKTAG('B', 'C', '4', 'S'):
212             ctx->tex_ratio = 8;
213             ctx->tex_funct = ctx->texdsp.rgtc1s_block;
214             break;
215         case MKTAG('A', 'T', 'I', '2'):
216             /* RGT2 variant with swapped R and G (3Dc)*/
217             ctx->tex_ratio = 16;
218             ctx->tex_funct = ctx->texdsp.dxn3dc_block;
219             break;
220         case MKTAG('B', 'C', '5', 'U'):
221             ctx->tex_ratio = 16;
222             ctx->tex_funct = ctx->texdsp.rgtc2u_block;
223             break;
224         case MKTAG('B', 'C', '5', 'S'):
225             ctx->tex_ratio = 16;
226             ctx->tex_funct = ctx->texdsp.rgtc2s_block;
227             break;
228         case MKTAG('U', 'Y', 'V', 'Y'):
229             ctx->compressed = 0;
230             avctx->pix_fmt = AV_PIX_FMT_UYVY422;
231             break;
232         case MKTAG('Y', 'U', 'Y', '2'):
233             ctx->compressed = 0;
234             avctx->pix_fmt = AV_PIX_FMT_YUYV422;
235             break;
236         case MKTAG('P', '8', ' ', ' '):
237             /* ATI Palette8, same as normal palette */
238             ctx->compressed = 0;
239             ctx->paletted   = 1;
240             avctx->pix_fmt  = AV_PIX_FMT_PAL8;
241             break;
242         case MKTAG('G', '1', ' ', ' '):
243             ctx->compressed = 0;
244             avctx->pix_fmt  = AV_PIX_FMT_MONOBLACK;
245             break;
246         case MKTAG('D', 'X', '1', '0'):
247             /* DirectX 10 extra header */
248             dxgi = bytestream2_get_le32(gbc);
249             bytestream2_skip(gbc, 4); // resourceDimension
250             bytestream2_skip(gbc, 4); // miscFlag
251             array = bytestream2_get_le32(gbc);
252             bytestream2_skip(gbc, 4); // miscFlag2
253 
254             if (array != 0)
255                 av_log(avctx, AV_LOG_VERBOSE,
256                        "Found array of size %d (ignored).\n", array);
257 
258             /* Only BC[1-5] are actually compressed. */
259             ctx->compressed = (dxgi >= 70) && (dxgi <= 84);
260 
261             av_log(avctx, AV_LOG_VERBOSE, "DXGI format %d.\n", dxgi);
262             switch (dxgi) {
263             /* RGB types. */
264             case DXGI_FORMAT_R16G16B16A16_TYPELESS:
265             case DXGI_FORMAT_R16G16B16A16_FLOAT:
266             case DXGI_FORMAT_R16G16B16A16_UNORM:
267             case DXGI_FORMAT_R16G16B16A16_UINT:
268             case DXGI_FORMAT_R16G16B16A16_SNORM:
269             case DXGI_FORMAT_R16G16B16A16_SINT:
270                 avctx->pix_fmt = AV_PIX_FMT_BGRA64;
271                 break;
272             case DXGI_FORMAT_R8G8B8A8_UNORM_SRGB:
273                 avctx->colorspace = AVCOL_SPC_RGB;
274             case DXGI_FORMAT_R8G8B8A8_TYPELESS:
275             case DXGI_FORMAT_R8G8B8A8_UNORM:
276             case DXGI_FORMAT_R8G8B8A8_UINT:
277             case DXGI_FORMAT_R8G8B8A8_SNORM:
278             case DXGI_FORMAT_R8G8B8A8_SINT:
279                 avctx->pix_fmt = AV_PIX_FMT_BGRA;
280                 break;
281             case DXGI_FORMAT_B8G8R8A8_UNORM_SRGB:
282                 avctx->colorspace = AVCOL_SPC_RGB;
283             case DXGI_FORMAT_B8G8R8A8_TYPELESS:
284             case DXGI_FORMAT_B8G8R8A8_UNORM:
285                 avctx->pix_fmt = AV_PIX_FMT_RGBA;
286                 break;
287             case DXGI_FORMAT_B8G8R8X8_UNORM_SRGB:
288                 avctx->colorspace = AVCOL_SPC_RGB;
289             case DXGI_FORMAT_B8G8R8X8_TYPELESS:
290             case DXGI_FORMAT_B8G8R8X8_UNORM:
291                 avctx->pix_fmt = AV_PIX_FMT_RGBA; // opaque
292                 break;
293             case DXGI_FORMAT_B5G6R5_UNORM:
294                 avctx->pix_fmt = AV_PIX_FMT_RGB565LE;
295                 break;
296             /* Texture types. */
297             case DXGI_FORMAT_BC1_UNORM_SRGB:
298                 avctx->colorspace = AVCOL_SPC_RGB;
299             case DXGI_FORMAT_BC1_TYPELESS:
300             case DXGI_FORMAT_BC1_UNORM:
301                 ctx->tex_ratio = 8;
302                 ctx->tex_funct = ctx->texdsp.dxt1a_block;
303                 break;
304             case DXGI_FORMAT_BC2_UNORM_SRGB:
305                 avctx->colorspace = AVCOL_SPC_RGB;
306             case DXGI_FORMAT_BC2_TYPELESS:
307             case DXGI_FORMAT_BC2_UNORM:
308                 ctx->tex_ratio = 16;
309                 ctx->tex_funct = ctx->texdsp.dxt3_block;
310                 break;
311             case DXGI_FORMAT_BC3_UNORM_SRGB:
312                 avctx->colorspace = AVCOL_SPC_RGB;
313             case DXGI_FORMAT_BC3_TYPELESS:
314             case DXGI_FORMAT_BC3_UNORM:
315                 ctx->tex_ratio = 16;
316                 ctx->tex_funct = ctx->texdsp.dxt5_block;
317                 break;
318             case DXGI_FORMAT_BC4_TYPELESS:
319             case DXGI_FORMAT_BC4_UNORM:
320                 ctx->tex_ratio = 8;
321                 ctx->tex_funct = ctx->texdsp.rgtc1u_block;
322                 break;
323             case DXGI_FORMAT_BC4_SNORM:
324                 ctx->tex_ratio = 8;
325                 ctx->tex_funct = ctx->texdsp.rgtc1s_block;
326                 break;
327             case DXGI_FORMAT_BC5_TYPELESS:
328             case DXGI_FORMAT_BC5_UNORM:
329                 ctx->tex_ratio = 16;
330                 ctx->tex_funct = ctx->texdsp.rgtc2u_block;
331                 break;
332             case DXGI_FORMAT_BC5_SNORM:
333                 ctx->tex_ratio = 16;
334                 ctx->tex_funct = ctx->texdsp.rgtc2s_block;
335                 break;
336             default:
337                 av_log(avctx, AV_LOG_ERROR,
338                        "Unsupported DXGI format %d.\n", dxgi);
339                 return AVERROR_INVALIDDATA;
340             }
341             break;
342         default:
343             av_log(avctx, AV_LOG_ERROR, "Unsupported %s fourcc.\n", av_fourcc2str(fourcc));
344             return AVERROR_INVALIDDATA;
345         }
346     } else if (ctx->paletted) {
347         if (bpp == 8) {
348             avctx->pix_fmt = AV_PIX_FMT_PAL8;
349         } else {
350             av_log(avctx, AV_LOG_ERROR, "Unsupported palette bpp %d.\n", bpp);
351             return AVERROR_INVALIDDATA;
352         }
353     } else {
354         /*  4 bpp */
355         if (bpp == 4 && r == 0 && g == 0 && b == 0 && a == 0)
356             avctx->pix_fmt = AV_PIX_FMT_PAL8;
357         /*  8 bpp */
358         else if (bpp == 8 && r == 0xff && g == 0 && b == 0 && a == 0)
359             avctx->pix_fmt = AV_PIX_FMT_GRAY8;
360         else if (bpp == 8 && r == 0 && g == 0 && b == 0 && a == 0xff)
361             avctx->pix_fmt = AV_PIX_FMT_GRAY8;
362         /* 16 bpp */
363         else if (bpp == 16 && r == 0xff && g == 0 && b == 0 && a == 0xff00)
364             avctx->pix_fmt = AV_PIX_FMT_YA8;
365         else if (bpp == 16 && r == 0xff00 && g == 0 && b == 0 && a == 0xff) {
366             avctx->pix_fmt = AV_PIX_FMT_YA8;
367             ctx->postproc = DDS_SWAP_ALPHA;
368         }
369         else if (bpp == 16 && r == 0xffff && g == 0 && b == 0 && a == 0)
370             avctx->pix_fmt = AV_PIX_FMT_GRAY16LE;
371         else if (bpp == 16 && r == 0x7c00 && g == 0x3e0 && b == 0x1f && a == 0)
372             avctx->pix_fmt = AV_PIX_FMT_RGB555LE;
373         else if (bpp == 16 && r == 0x7c00 && g == 0x3e0 && b == 0x1f && a == 0x8000)
374             avctx->pix_fmt = AV_PIX_FMT_RGB555LE; // alpha ignored
375         else if (bpp == 16 && r == 0xf800 && g == 0x7e0 && b == 0x1f && a == 0)
376             avctx->pix_fmt = AV_PIX_FMT_RGB565LE;
377         /* 24 bpp */
378         else if (bpp == 24 && r == 0xff0000 && g == 0xff00 && b == 0xff && a == 0)
379             avctx->pix_fmt = AV_PIX_FMT_BGR24;
380         /* 32 bpp */
381         else if (bpp == 32 && r == 0xff0000 && g == 0xff00 && b == 0xff && a == 0)
382             avctx->pix_fmt = AV_PIX_FMT_BGR0; // opaque
383         else if (bpp == 32 && r == 0xff && g == 0xff00 && b == 0xff0000 && a == 0)
384             avctx->pix_fmt = AV_PIX_FMT_RGB0; // opaque
385         else if (bpp == 32 && r == 0xff0000 && g == 0xff00 && b == 0xff && a == 0xff000000)
386             avctx->pix_fmt = AV_PIX_FMT_BGRA;
387         else if (bpp == 32 && r == 0xff && g == 0xff00 && b == 0xff0000 && a == 0xff000000)
388             avctx->pix_fmt = AV_PIX_FMT_RGBA;
389         /* give up */
390         else {
391             av_log(avctx, AV_LOG_ERROR, "Unknown pixel format "
392                    "[bpp %d r 0x%x g 0x%x b 0x%x a 0x%x].\n", bpp, r, g, b, a);
393             return AVERROR_INVALIDDATA;
394         }
395     }
396 
397     /* Set any remaining post-proc that should happen before frame is ready. */
398     if (alpha_exponent)
399         ctx->postproc = DDS_ALPHA_EXP;
400     else if (normal_map)
401         ctx->postproc = DDS_NORMAL_MAP;
402     else if (ycocg_classic && !ctx->compressed)
403         ctx->postproc = DDS_RAW_YCOCG;
404 
405     /* ATI/NVidia variants sometimes add swizzling in bpp. */
406     switch (bpp) {
407     case MKTAG('A', '2', 'X', 'Y'):
408         ctx->postproc = DDS_SWIZZLE_A2XY;
409         break;
410     case MKTAG('x', 'G', 'B', 'R'):
411         ctx->postproc = DDS_SWIZZLE_XGBR;
412         break;
413     case MKTAG('x', 'R', 'B', 'G'):
414         ctx->postproc = DDS_SWIZZLE_XRBG;
415         break;
416     case MKTAG('R', 'B', 'x', 'G'):
417         ctx->postproc = DDS_SWIZZLE_RBXG;
418         break;
419     case MKTAG('R', 'G', 'x', 'B'):
420         ctx->postproc = DDS_SWIZZLE_RGXB;
421         break;
422     case MKTAG('R', 'x', 'B', 'G'):
423         ctx->postproc = DDS_SWIZZLE_RXBG;
424         break;
425     case MKTAG('x', 'G', 'x', 'R'):
426         ctx->postproc = DDS_SWIZZLE_XGXR;
427         break;
428     case MKTAG('A', '2', 'D', '5'):
429         ctx->postproc = DDS_NORMAL_MAP;
430         break;
431     }
432 
433     return 0;
434 }
435 
decompress_texture_thread(AVCodecContext * avctx,void * arg,int slice,int thread_nb)436 static int decompress_texture_thread(AVCodecContext *avctx, void *arg,
437                                      int slice, int thread_nb)
438 {
439     DDSContext *ctx = avctx->priv_data;
440     AVFrame *frame = arg;
441     const uint8_t *d = ctx->tex_data;
442     int w_block = avctx->coded_width / TEXTURE_BLOCK_W;
443     int h_block = avctx->coded_height / TEXTURE_BLOCK_H;
444     int x, y;
445     int start_slice, end_slice;
446     int base_blocks_per_slice = h_block / ctx->slice_count;
447     int remainder_blocks = h_block % ctx->slice_count;
448 
449     /* When the frame height (in blocks) doesn't divide evenly between the
450      * number of slices, spread the remaining blocks evenly between the first
451      * operations */
452     start_slice = slice * base_blocks_per_slice;
453     /* Add any extra blocks (one per slice) that have been added before this slice */
454     start_slice += FFMIN(slice, remainder_blocks);
455 
456     end_slice = start_slice + base_blocks_per_slice;
457     /* Add an extra block if there are still remainder blocks to be accounted for */
458     if (slice < remainder_blocks)
459         end_slice++;
460 
461     for (y = start_slice; y < end_slice; y++) {
462         uint8_t *p = frame->data[0] + y * frame->linesize[0] * TEXTURE_BLOCK_H;
463         int off  = y * w_block;
464         for (x = 0; x < w_block; x++) {
465             ctx->tex_funct(p + x * 16, frame->linesize[0],
466                            d + (off + x) * ctx->tex_ratio);
467         }
468     }
469 
470     return 0;
471 }
472 
do_swizzle(AVFrame * frame,int x,int y)473 static void do_swizzle(AVFrame *frame, int x, int y)
474 {
475     int i;
476     for (i = 0; i < frame->linesize[0] * frame->height; i += 4) {
477         uint8_t *src = frame->data[0] + i;
478         FFSWAP(uint8_t, src[x], src[y]);
479     }
480 }
481 
run_postproc(AVCodecContext * avctx,AVFrame * frame)482 static void run_postproc(AVCodecContext *avctx, AVFrame *frame)
483 {
484     DDSContext *ctx = avctx->priv_data;
485     int i, x_off;
486 
487     switch (ctx->postproc) {
488     case DDS_ALPHA_EXP:
489         /* Alpha-exponential mode divides each channel by the maximum
490          * R, G or B value, and stores the multiplying factor in the
491          * alpha channel. */
492         av_log(avctx, AV_LOG_DEBUG, "Post-processing alpha exponent.\n");
493 
494         for (i = 0; i < frame->linesize[0] * frame->height; i += 4) {
495             uint8_t *src = frame->data[0] + i;
496             int r = src[0];
497             int g = src[1];
498             int b = src[2];
499             int a = src[3];
500 
501             src[0] = r * a / 255;
502             src[1] = g * a / 255;
503             src[2] = b * a / 255;
504             src[3] = 255;
505         }
506         break;
507     case DDS_NORMAL_MAP:
508         /* Normal maps work in the XYZ color space and they encode
509          * X in R or in A, depending on the texture type, Y in G and
510          * derive Z with a square root of the distance.
511          *
512          * http://www.realtimecollisiondetection.net/blog/?p=28 */
513         av_log(avctx, AV_LOG_DEBUG, "Post-processing normal map.\n");
514 
515         x_off = ctx->tex_ratio == 8 ? 0 : 3;
516         for (i = 0; i < frame->linesize[0] * frame->height; i += 4) {
517             uint8_t *src = frame->data[0] + i;
518             int x = src[x_off];
519             int y = src[1];
520             int z = 127;
521 
522             int d = (255 * 255 - x * x - y * y) / 2;
523             if (d > 0)
524                 z = lrint(sqrtf(d));
525 
526             src[0] = x;
527             src[1] = y;
528             src[2] = z;
529             src[3] = 255;
530         }
531         break;
532     case DDS_RAW_YCOCG:
533         /* Data is Y-Co-Cg-A and not RGBA, but they are represented
534          * with the same masks in the DDPF header. */
535         av_log(avctx, AV_LOG_DEBUG, "Post-processing raw YCoCg.\n");
536 
537         for (i = 0; i < frame->linesize[0] * frame->height; i += 4) {
538             uint8_t *src = frame->data[0] + i;
539             int a  = src[0];
540             int cg = src[1] - 128;
541             int co = src[2] - 128;
542             int y  = src[3];
543 
544             src[0] = av_clip_uint8(y + co - cg);
545             src[1] = av_clip_uint8(y + cg);
546             src[2] = av_clip_uint8(y - co - cg);
547             src[3] = a;
548         }
549         break;
550     case DDS_SWAP_ALPHA:
551         /* Alpha and Luma are stored swapped. */
552         av_log(avctx, AV_LOG_DEBUG, "Post-processing swapped Luma/Alpha.\n");
553 
554         for (i = 0; i < frame->linesize[0] * frame->height; i += 2) {
555             uint8_t *src = frame->data[0] + i;
556             FFSWAP(uint8_t, src[0], src[1]);
557         }
558         break;
559     case DDS_SWIZZLE_A2XY:
560         /* Swap R and G, often used to restore a standard RGTC2. */
561         av_log(avctx, AV_LOG_DEBUG, "Post-processing A2XY swizzle.\n");
562         do_swizzle(frame, 0, 1);
563         break;
564     case DDS_SWIZZLE_RBXG:
565         /* Swap G and A, then B and new A (G). */
566         av_log(avctx, AV_LOG_DEBUG, "Post-processing RBXG swizzle.\n");
567         do_swizzle(frame, 1, 3);
568         do_swizzle(frame, 2, 3);
569         break;
570     case DDS_SWIZZLE_RGXB:
571         /* Swap B and A. */
572         av_log(avctx, AV_LOG_DEBUG, "Post-processing RGXB swizzle.\n");
573         do_swizzle(frame, 2, 3);
574         break;
575     case DDS_SWIZZLE_RXBG:
576         /* Swap G and A. */
577         av_log(avctx, AV_LOG_DEBUG, "Post-processing RXBG swizzle.\n");
578         do_swizzle(frame, 1, 3);
579         break;
580     case DDS_SWIZZLE_RXGB:
581         /* Swap R and A (misleading name). */
582         av_log(avctx, AV_LOG_DEBUG, "Post-processing RXGB swizzle.\n");
583         do_swizzle(frame, 0, 3);
584         break;
585     case DDS_SWIZZLE_XGBR:
586         /* Swap B and A, then R and new A (B). */
587         av_log(avctx, AV_LOG_DEBUG, "Post-processing XGBR swizzle.\n");
588         do_swizzle(frame, 2, 3);
589         do_swizzle(frame, 0, 3);
590         break;
591     case DDS_SWIZZLE_XGXR:
592         /* Swap G and A, then R and new A (G), then new R (G) and new G (A).
593          * This variant does not store any B component. */
594         av_log(avctx, AV_LOG_DEBUG, "Post-processing XGXR swizzle.\n");
595         do_swizzle(frame, 1, 3);
596         do_swizzle(frame, 0, 3);
597         do_swizzle(frame, 0, 1);
598         break;
599     case DDS_SWIZZLE_XRBG:
600         /* Swap G and A, then R and new A (G). */
601         av_log(avctx, AV_LOG_DEBUG, "Post-processing XRBG swizzle.\n");
602         do_swizzle(frame, 1, 3);
603         do_swizzle(frame, 0, 3);
604         break;
605     }
606 }
607 
dds_decode(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)608 static int dds_decode(AVCodecContext *avctx, void *data,
609                       int *got_frame, AVPacket *avpkt)
610 {
611     DDSContext *ctx = avctx->priv_data;
612     GetByteContext *gbc = &ctx->gbc;
613     AVFrame *frame = data;
614     int mipmap;
615     int ret;
616     int width, height;
617 
618     ff_texturedsp_init(&ctx->texdsp);
619     bytestream2_init(gbc, avpkt->data, avpkt->size);
620 
621     if (bytestream2_get_bytes_left(gbc) < 128) {
622         av_log(avctx, AV_LOG_ERROR, "Frame is too small (%d).\n",
623                bytestream2_get_bytes_left(gbc));
624         return AVERROR_INVALIDDATA;
625     }
626 
627     if (bytestream2_get_le32(gbc) != MKTAG('D', 'D', 'S', ' ') ||
628         bytestream2_get_le32(gbc) != 124) { // header size
629         av_log(avctx, AV_LOG_ERROR, "Invalid DDS header.\n");
630         return AVERROR_INVALIDDATA;
631     }
632 
633     bytestream2_skip(gbc, 4); // flags
634 
635     height = bytestream2_get_le32(gbc);
636     width  = bytestream2_get_le32(gbc);
637     ret = ff_set_dimensions(avctx, width, height);
638     if (ret < 0) {
639         av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
640                avctx->width, avctx->height);
641         return ret;
642     }
643 
644     /* Since codec is based on 4x4 blocks, size is aligned to 4. */
645     avctx->coded_width  = FFALIGN(avctx->width,  TEXTURE_BLOCK_W);
646     avctx->coded_height = FFALIGN(avctx->height, TEXTURE_BLOCK_H);
647 
648     bytestream2_skip(gbc, 4); // pitch
649     bytestream2_skip(gbc, 4); // depth
650     mipmap = bytestream2_get_le32(gbc);
651     if (mipmap != 0)
652         av_log(avctx, AV_LOG_VERBOSE, "Found %d mipmaps (ignored).\n", mipmap);
653 
654     /* Extract pixel format information, considering additional elements
655      * in reserved1 and reserved2. */
656     ret = parse_pixel_format(avctx);
657     if (ret < 0)
658         return ret;
659 
660     ret = ff_get_buffer(avctx, frame, 0);
661     if (ret < 0)
662         return ret;
663 
664     if (ctx->compressed) {
665         int size = (avctx->coded_height / TEXTURE_BLOCK_H) *
666                    (avctx->coded_width / TEXTURE_BLOCK_W) * ctx->tex_ratio;
667         ctx->slice_count = av_clip(avctx->thread_count, 1,
668                                    avctx->coded_height / TEXTURE_BLOCK_H);
669 
670         if (bytestream2_get_bytes_left(gbc) < size) {
671             av_log(avctx, AV_LOG_ERROR,
672                    "Compressed Buffer is too small (%d < %d).\n",
673                    bytestream2_get_bytes_left(gbc), size);
674             return AVERROR_INVALIDDATA;
675         }
676 
677         /* Use the decompress function on the texture, one block per thread. */
678         ctx->tex_data = gbc->buffer;
679         avctx->execute2(avctx, decompress_texture_thread, frame, NULL, ctx->slice_count);
680     } else if (!ctx->paletted && ctx->bpp == 4 && avctx->pix_fmt == AV_PIX_FMT_PAL8) {
681         uint8_t *dst = frame->data[0];
682         int x, y, i;
683 
684         /* Use the first 64 bytes as palette, then copy the rest. */
685         bytestream2_get_buffer(gbc, frame->data[1], 16 * 4);
686         for (i = 0; i < 16; i++) {
687             AV_WN32(frame->data[1] + i*4,
688                     (frame->data[1][2+i*4]<<0)+
689                     (frame->data[1][1+i*4]<<8)+
690                     (frame->data[1][0+i*4]<<16)+
691                     ((unsigned)frame->data[1][3+i*4]<<24)
692             );
693         }
694         frame->palette_has_changed = 1;
695 
696         if (bytestream2_get_bytes_left(gbc) < frame->height * frame->width / 2) {
697             av_log(avctx, AV_LOG_ERROR, "Buffer is too small (%d < %d).\n",
698                    bytestream2_get_bytes_left(gbc), frame->height * frame->width / 2);
699             return AVERROR_INVALIDDATA;
700         }
701 
702         for (y = 0; y < frame->height; y++) {
703             for (x = 0; x < frame->width; x += 2) {
704                 uint8_t val = bytestream2_get_byte(gbc);
705                 dst[x    ] = val & 0xF;
706                 dst[x + 1] = val >> 4;
707             }
708             dst += frame->linesize[0];
709         }
710     } else {
711         int linesize = av_image_get_linesize(avctx->pix_fmt, frame->width, 0);
712 
713         if (ctx->paletted) {
714             int i;
715             /* Use the first 1024 bytes as palette, then copy the rest. */
716             bytestream2_get_buffer(gbc, frame->data[1], 256 * 4);
717             for (i = 0; i < 256; i++)
718                 AV_WN32(frame->data[1] + i*4,
719                         (frame->data[1][2+i*4]<<0)+
720                         (frame->data[1][1+i*4]<<8)+
721                         (frame->data[1][0+i*4]<<16)+
722                         ((unsigned)frame->data[1][3+i*4]<<24)
723                 );
724 
725             frame->palette_has_changed = 1;
726         }
727 
728         if (bytestream2_get_bytes_left(gbc) < frame->height * linesize) {
729             av_log(avctx, AV_LOG_ERROR, "Buffer is too small (%d < %d).\n",
730                    bytestream2_get_bytes_left(gbc), frame->height * linesize);
731             return AVERROR_INVALIDDATA;
732         }
733 
734         av_image_copy_plane(frame->data[0], frame->linesize[0],
735                             gbc->buffer, linesize,
736                             linesize, frame->height);
737     }
738 
739     /* Run any post processing here if needed. */
740     if (ctx->postproc != DDS_NONE)
741         run_postproc(avctx, frame);
742 
743     /* Frame is ready to be output. */
744     frame->pict_type = AV_PICTURE_TYPE_I;
745     frame->key_frame = 1;
746     *got_frame = 1;
747 
748     return avpkt->size;
749 }
750 
751 AVCodec ff_dds_decoder = {
752     .name           = "dds",
753     .long_name      = NULL_IF_CONFIG_SMALL("DirectDraw Surface image decoder"),
754     .type           = AVMEDIA_TYPE_VIDEO,
755     .id             = AV_CODEC_ID_DDS,
756     .decode         = dds_decode,
757     .priv_data_size = sizeof(DDSContext),
758     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SLICE_THREADS,
759     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE
760 };
761