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