1 /*
2  * Copyright (c) 2021 Paul B Mahol
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * OpenEXR encoder
24  */
25 
26 #include <float.h>
27 #include <zlib.h>
28 
29 #include "libavutil/avassert.h"
30 #include "libavutil/opt.h"
31 #include "libavutil/intreadwrite.h"
32 #include "libavutil/imgutils.h"
33 #include "libavutil/pixdesc.h"
34 #include "avcodec.h"
35 #include "bytestream.h"
36 #include "internal.h"
37 #include "float2half.h"
38 
39 enum ExrCompr {
40     EXR_RAW,
41     EXR_RLE,
42     EXR_ZIP1,
43     EXR_ZIP16,
44     EXR_NBCOMPR,
45 };
46 
47 enum ExrPixelType {
48     EXR_UINT,
49     EXR_HALF,
50     EXR_FLOAT,
51     EXR_UNKNOWN,
52 };
53 
54 static const char abgr_chlist[4] = { 'A', 'B', 'G', 'R' };
55 static const char bgr_chlist[4] = { 'B', 'G', 'R', 'A' };
56 static const uint8_t gbra_order[4] = { 3, 1, 0, 2 };
57 static const uint8_t gbr_order[4] = { 1, 0, 2, 0 };
58 
59 typedef struct EXRScanlineData {
60     uint8_t *compressed_data;
61     unsigned int compressed_size;
62 
63     uint8_t *uncompressed_data;
64     unsigned int uncompressed_size;
65 
66     uint8_t *tmp;
67     unsigned int tmp_size;
68 
69     int64_t actual_size;
70 } EXRScanlineData;
71 
72 typedef struct EXRContext {
73     const AVClass *class;
74 
75     int compression;
76     int pixel_type;
77     int planes;
78     int nb_scanlines;
79     int scanline_height;
80     float gamma;
81     const char *ch_names;
82     const uint8_t *ch_order;
83     PutByteContext pb;
84 
85     EXRScanlineData *scanline;
86 
87     uint16_t basetable[512];
88     uint8_t shifttable[512];
89 } EXRContext;
90 
encode_init(AVCodecContext * avctx)91 static int encode_init(AVCodecContext *avctx)
92 {
93     EXRContext *s = avctx->priv_data;
94 
95     float2half_tables(s->basetable, s->shifttable);
96 
97     switch (avctx->pix_fmt) {
98     case AV_PIX_FMT_GBRPF32:
99         s->planes = 3;
100         s->ch_names = bgr_chlist;
101         s->ch_order = gbr_order;
102         break;
103     case AV_PIX_FMT_GBRAPF32:
104         s->planes = 4;
105         s->ch_names = abgr_chlist;
106         s->ch_order = gbra_order;
107         break;
108     default:
109         av_assert0(0);
110     }
111 
112     switch (s->compression) {
113     case EXR_RAW:
114     case EXR_RLE:
115     case EXR_ZIP1:
116         s->scanline_height = 1;
117         s->nb_scanlines = avctx->height;
118         break;
119     case EXR_ZIP16:
120         s->scanline_height = 16;
121         s->nb_scanlines = (avctx->height + s->scanline_height - 1) / s->scanline_height;
122         break;
123     default:
124         av_assert0(0);
125     }
126 
127     s->scanline = av_calloc(s->nb_scanlines, sizeof(*s->scanline));
128     if (!s->scanline)
129         return AVERROR(ENOMEM);
130 
131     return 0;
132 }
133 
encode_close(AVCodecContext * avctx)134 static int encode_close(AVCodecContext *avctx)
135 {
136     EXRContext *s = avctx->priv_data;
137 
138     for (int y = 0; y < s->nb_scanlines && s->scanline; y++) {
139         EXRScanlineData *scanline = &s->scanline[y];
140 
141         av_freep(&scanline->tmp);
142         av_freep(&scanline->compressed_data);
143         av_freep(&scanline->uncompressed_data);
144     }
145 
146     av_freep(&s->scanline);
147 
148     return 0;
149 }
150 
reorder_pixels(uint8_t * dst,const uint8_t * src,ptrdiff_t size)151 static void reorder_pixels(uint8_t *dst, const uint8_t *src, ptrdiff_t size)
152 {
153     const ptrdiff_t half_size = (size + 1) / 2;
154     uint8_t *t1 = dst;
155     uint8_t *t2 = dst + half_size;
156 
157     for (ptrdiff_t i = 0; i < half_size; i++) {
158         t1[i] = *(src++);
159         t2[i] = *(src++);
160     }
161 }
162 
predictor(uint8_t * src,ptrdiff_t size)163 static void predictor(uint8_t *src, ptrdiff_t size)
164 {
165     int p = src[0];
166 
167     for (ptrdiff_t i = 1; i < size; i++) {
168         int d = src[i] - p + 384;
169 
170         p = src[i];
171         src[i] = d;
172     }
173 }
174 
rle_compress(uint8_t * out,int64_t out_size,const uint8_t * in,int64_t in_size)175 static int64_t rle_compress(uint8_t *out, int64_t out_size,
176                             const uint8_t *in, int64_t in_size)
177 {
178     int64_t i = 0, o = 0, run = 1, copy = 0;
179 
180     while (i < in_size) {
181         while (i + run < in_size && in[i] == in[i + run] && run < 128)
182             run++;
183 
184         if (run >= 3) {
185             if (o + 2 >= out_size)
186                 return -1;
187             out[o++] = run - 1;
188             out[o++] = in[i];
189             i += run;
190         } else {
191             if (i + run < in_size)
192                 copy += run;
193             while (i + copy < in_size && copy < 127 && in[i + copy] != in[i + copy - 1])
194                 copy++;
195 
196             if (o + 1 + copy >= out_size)
197                 return -1;
198             out[o++] = -copy;
199 
200             for (int x = 0; x < copy; x++)
201                 out[o + x] = in[i + x];
202 
203             o += copy;
204             i += copy;
205             copy = 0;
206         }
207 
208         run = 1;
209     }
210 
211     return o;
212 }
213 
encode_scanline_rle(EXRContext * s,const AVFrame * frame)214 static int encode_scanline_rle(EXRContext *s, const AVFrame *frame)
215 {
216     const int64_t element_size = s->pixel_type == EXR_HALF ? 2LL : 4LL;
217 
218     for (int y = 0; y < frame->height; y++) {
219         EXRScanlineData *scanline = &s->scanline[y];
220         int64_t tmp_size = element_size * s->planes * frame->width;
221         int64_t max_compressed_size = tmp_size * 3 / 2;
222 
223         av_fast_padded_malloc(&scanline->uncompressed_data, &scanline->uncompressed_size, tmp_size);
224         if (!scanline->uncompressed_data)
225             return AVERROR(ENOMEM);
226 
227         av_fast_padded_malloc(&scanline->tmp, &scanline->tmp_size, tmp_size);
228         if (!scanline->tmp)
229             return AVERROR(ENOMEM);
230 
231         av_fast_padded_malloc(&scanline->compressed_data, &scanline->compressed_size, max_compressed_size);
232         if (!scanline->compressed_data)
233             return AVERROR(ENOMEM);
234 
235         switch (s->pixel_type) {
236         case EXR_FLOAT:
237             for (int p = 0; p < s->planes; p++) {
238                 int ch = s->ch_order[p];
239 
240                 memcpy(scanline->uncompressed_data + frame->width * 4 * p,
241                        frame->data[ch] + y * frame->linesize[ch], frame->width * 4);
242             }
243             break;
244         case EXR_HALF:
245             for (int p = 0; p < s->planes; p++) {
246                 int ch = s->ch_order[p];
247                 uint16_t *dst = (uint16_t *)(scanline->uncompressed_data + frame->width * 2 * p);
248                 uint32_t *src = (uint32_t *)(frame->data[ch] + y * frame->linesize[ch]);
249 
250                 for (int x = 0; x < frame->width; x++)
251                     dst[x] = float2half(src[x], s->basetable, s->shifttable);
252             }
253             break;
254         }
255 
256         reorder_pixels(scanline->tmp, scanline->uncompressed_data, tmp_size);
257         predictor(scanline->tmp, tmp_size);
258         scanline->actual_size = rle_compress(scanline->compressed_data,
259                                              max_compressed_size,
260                                              scanline->tmp, tmp_size);
261 
262         if (scanline->actual_size <= 0 || scanline->actual_size >= tmp_size) {
263             FFSWAP(uint8_t *, scanline->uncompressed_data, scanline->compressed_data);
264             FFSWAP(int, scanline->uncompressed_size, scanline->compressed_size);
265             scanline->actual_size = tmp_size;
266         }
267     }
268 
269     return 0;
270 }
271 
encode_scanline_zip(EXRContext * s,const AVFrame * frame)272 static int encode_scanline_zip(EXRContext *s, const AVFrame *frame)
273 {
274     const int64_t element_size = s->pixel_type == EXR_HALF ? 2LL : 4LL;
275 
276     for (int y = 0; y < s->nb_scanlines; y++) {
277         EXRScanlineData *scanline = &s->scanline[y];
278         const int scanline_height = FFMIN(s->scanline_height, frame->height - y * s->scanline_height);
279         int64_t tmp_size = element_size * s->planes * frame->width * scanline_height;
280         int64_t max_compressed_size = tmp_size * 3 / 2;
281         unsigned long actual_size, source_size;
282 
283         av_fast_padded_malloc(&scanline->uncompressed_data, &scanline->uncompressed_size, tmp_size);
284         if (!scanline->uncompressed_data)
285             return AVERROR(ENOMEM);
286 
287         av_fast_padded_malloc(&scanline->tmp, &scanline->tmp_size, tmp_size);
288         if (!scanline->tmp)
289             return AVERROR(ENOMEM);
290 
291         av_fast_padded_malloc(&scanline->compressed_data, &scanline->compressed_size, max_compressed_size);
292         if (!scanline->compressed_data)
293             return AVERROR(ENOMEM);
294 
295         switch (s->pixel_type) {
296         case EXR_FLOAT:
297             for (int l = 0; l < scanline_height; l++) {
298                 const int scanline_size = frame->width * 4 * s->planes;
299 
300                 for (int p = 0; p < s->planes; p++) {
301                     int ch = s->ch_order[p];
302 
303                     memcpy(scanline->uncompressed_data + scanline_size * l + p * frame->width * 4,
304                            frame->data[ch] + (y * s->scanline_height + l) * frame->linesize[ch],
305                            frame->width * 4);
306                 }
307             }
308             break;
309         case EXR_HALF:
310             for (int l = 0; l < scanline_height; l++) {
311                 const int scanline_size = frame->width * 2 * s->planes;
312 
313                 for (int p = 0; p < s->planes; p++) {
314                     int ch = s->ch_order[p];
315                     uint16_t *dst = (uint16_t *)(scanline->uncompressed_data + scanline_size * l + p * frame->width * 2);
316                     uint32_t *src = (uint32_t *)(frame->data[ch] + (y * s->scanline_height + l) * frame->linesize[ch]);
317 
318                     for (int x = 0; x < frame->width; x++)
319                         dst[x] = float2half(src[x], s->basetable, s->shifttable);
320                 }
321             }
322             break;
323         }
324 
325         reorder_pixels(scanline->tmp, scanline->uncompressed_data, tmp_size);
326         predictor(scanline->tmp, tmp_size);
327         source_size = tmp_size;
328         actual_size = max_compressed_size;
329         compress(scanline->compressed_data, &actual_size,
330                  scanline->tmp, source_size);
331 
332         scanline->actual_size = actual_size;
333         if (scanline->actual_size >= tmp_size) {
334             FFSWAP(uint8_t *, scanline->uncompressed_data, scanline->compressed_data);
335             FFSWAP(int, scanline->uncompressed_size, scanline->compressed_size);
336             scanline->actual_size = tmp_size;
337         }
338     }
339 
340     return 0;
341 }
342 
encode_frame(AVCodecContext * avctx,AVPacket * pkt,const AVFrame * frame,int * got_packet)343 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
344                         const AVFrame *frame, int *got_packet)
345 {
346     EXRContext *s = avctx->priv_data;
347     PutByteContext *pb = &s->pb;
348     int64_t offset;
349     int ret;
350     int64_t out_size = 2048LL + avctx->height * 16LL +
351                       av_image_get_buffer_size(avctx->pix_fmt,
352                                                avctx->width,
353                                                avctx->height, 64) * 3LL / 2;
354 
355     if ((ret = ff_alloc_packet2(avctx, pkt, out_size, out_size)) < 0)
356         return ret;
357 
358     bytestream2_init_writer(pb, pkt->data, pkt->size);
359 
360     bytestream2_put_le32(pb, 20000630);
361     bytestream2_put_byte(pb, 2);
362     bytestream2_put_le24(pb, 0);
363     bytestream2_put_buffer(pb, "channels\0chlist\0", 16);
364     bytestream2_put_le32(pb, s->planes * 18 + 1);
365 
366     for (int p = 0; p < s->planes; p++) {
367         bytestream2_put_byte(pb, s->ch_names[p]);
368         bytestream2_put_byte(pb, 0);
369         bytestream2_put_le32(pb, s->pixel_type);
370         bytestream2_put_le32(pb, 0);
371         bytestream2_put_le32(pb, 1);
372         bytestream2_put_le32(pb, 1);
373     }
374     bytestream2_put_byte(pb, 0);
375 
376     bytestream2_put_buffer(pb, "compression\0compression\0", 24);
377     bytestream2_put_le32(pb, 1);
378     bytestream2_put_byte(pb, s->compression);
379 
380     bytestream2_put_buffer(pb, "dataWindow\0box2i\0", 17);
381     bytestream2_put_le32(pb, 16);
382     bytestream2_put_le32(pb, 0);
383     bytestream2_put_le32(pb, 0);
384     bytestream2_put_le32(pb, avctx->width - 1);
385     bytestream2_put_le32(pb, avctx->height - 1);
386 
387     bytestream2_put_buffer(pb, "displayWindow\0box2i\0", 20);
388     bytestream2_put_le32(pb, 16);
389     bytestream2_put_le32(pb, 0);
390     bytestream2_put_le32(pb, 0);
391     bytestream2_put_le32(pb, avctx->width - 1);
392     bytestream2_put_le32(pb, avctx->height - 1);
393 
394     bytestream2_put_buffer(pb, "lineOrder\0lineOrder\0", 20);
395     bytestream2_put_le32(pb, 1);
396     bytestream2_put_byte(pb, 0);
397 
398     bytestream2_put_buffer(pb, "screenWindowCenter\0v2f\0", 23);
399     bytestream2_put_le32(pb, 8);
400     bytestream2_put_le64(pb, 0);
401 
402     bytestream2_put_buffer(pb, "screenWindowWidth\0float\0", 24);
403     bytestream2_put_le32(pb, 4);
404     bytestream2_put_le32(pb, av_float2int(1.f));
405 
406     if (avctx->sample_aspect_ratio.num && avctx->sample_aspect_ratio.den) {
407         bytestream2_put_buffer(pb, "pixelAspectRatio\0float\0", 23);
408         bytestream2_put_le32(pb, 4);
409         bytestream2_put_le32(pb, av_float2int(av_q2d(avctx->sample_aspect_ratio)));
410     }
411 
412     if (avctx->framerate.num && avctx->framerate.den) {
413         bytestream2_put_buffer(pb, "framesPerSecond\0rational\0", 25);
414         bytestream2_put_le32(pb, 8);
415         bytestream2_put_le32(pb, avctx->framerate.num);
416         bytestream2_put_le32(pb, avctx->framerate.den);
417     }
418 
419     bytestream2_put_buffer(pb, "gamma\0float\0", 12);
420     bytestream2_put_le32(pb, 4);
421     bytestream2_put_le32(pb, av_float2int(s->gamma));
422 
423     bytestream2_put_buffer(pb, "writer\0string\0", 14);
424     bytestream2_put_le32(pb, 4);
425     bytestream2_put_buffer(pb, "lavc", 4);
426     bytestream2_put_byte(pb, 0);
427 
428     switch (s->compression) {
429     case EXR_RAW:
430         /* nothing to do */
431         break;
432     case EXR_RLE:
433         encode_scanline_rle(s, frame);
434         break;
435     case EXR_ZIP16:
436     case EXR_ZIP1:
437         encode_scanline_zip(s, frame);
438         break;
439     default:
440         av_assert0(0);
441     }
442 
443     switch (s->compression) {
444     case EXR_RAW:
445         offset = bytestream2_tell_p(pb) + avctx->height * 8LL;
446 
447         if (s->pixel_type == EXR_FLOAT) {
448 
449             for (int y = 0; y < avctx->height; y++) {
450                 bytestream2_put_le64(pb, offset);
451                 offset += avctx->width * s->planes * 4 + 8;
452             }
453 
454             for (int y = 0; y < avctx->height; y++) {
455                 bytestream2_put_le32(pb, y);
456                 bytestream2_put_le32(pb, s->planes * avctx->width * 4);
457                 for (int p = 0; p < s->planes; p++) {
458                     int ch = s->ch_order[p];
459                     bytestream2_put_buffer(pb, frame->data[ch] + y * frame->linesize[ch],
460                                            avctx->width * 4);
461                 }
462             }
463         } else {
464             for (int y = 0; y < avctx->height; y++) {
465                 bytestream2_put_le64(pb, offset);
466                 offset += avctx->width * s->planes * 2 + 8;
467             }
468 
469             for (int y = 0; y < avctx->height; y++) {
470                 bytestream2_put_le32(pb, y);
471                 bytestream2_put_le32(pb, s->planes * avctx->width * 2);
472                 for (int p = 0; p < s->planes; p++) {
473                     int ch = s->ch_order[p];
474                     uint32_t *src = (uint32_t *)(frame->data[ch] + y * frame->linesize[ch]);
475 
476                     for (int x = 0; x < frame->width; x++)
477                         bytestream2_put_le16(pb, float2half(src[x], s->basetable, s->shifttable));
478                 }
479             }
480         }
481         break;
482     case EXR_ZIP16:
483     case EXR_ZIP1:
484     case EXR_RLE:
485         offset = bytestream2_tell_p(pb) + s->nb_scanlines * 8LL;
486 
487         for (int y = 0; y < s->nb_scanlines; y++) {
488             EXRScanlineData *scanline = &s->scanline[y];
489 
490             bytestream2_put_le64(pb, offset);
491             offset += scanline->actual_size + 8;
492         }
493 
494         for (int y = 0; y < s->nb_scanlines; y++) {
495             EXRScanlineData *scanline = &s->scanline[y];
496 
497             bytestream2_put_le32(pb, y * s->scanline_height);
498             bytestream2_put_le32(pb, scanline->actual_size);
499             bytestream2_put_buffer(pb, scanline->compressed_data,
500                                    scanline->actual_size);
501         }
502         break;
503     default:
504         av_assert0(0);
505     }
506 
507     av_shrink_packet(pkt, bytestream2_tell_p(pb));
508 
509     pkt->flags |= AV_PKT_FLAG_KEY;
510     *got_packet = 1;
511 
512     return 0;
513 }
514 
515 #define OFFSET(x) offsetof(EXRContext, x)
516 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
517 static const AVOption options[] = {
518     { "compression", "set compression type", OFFSET(compression), AV_OPT_TYPE_INT,   {.i64=0}, 0, EXR_NBCOMPR-1, VE, "compr" },
519     { "none",        "none",                 0,                   AV_OPT_TYPE_CONST, {.i64=EXR_RAW}, 0, 0, VE, "compr" },
520     { "rle" ,        "RLE",                  0,                   AV_OPT_TYPE_CONST, {.i64=EXR_RLE}, 0, 0, VE, "compr" },
521     { "zip1",        "ZIP1",                 0,                   AV_OPT_TYPE_CONST, {.i64=EXR_ZIP1}, 0, 0, VE, "compr" },
522     { "zip16",       "ZIP16",                0,                   AV_OPT_TYPE_CONST, {.i64=EXR_ZIP16}, 0, 0, VE, "compr" },
523     { "format", "set pixel type", OFFSET(pixel_type), AV_OPT_TYPE_INT,   {.i64=EXR_FLOAT}, EXR_HALF, EXR_UNKNOWN-1, VE, "pixel" },
524     { "half" ,       NULL,                   0,                   AV_OPT_TYPE_CONST, {.i64=EXR_HALF},  0, 0, VE, "pixel" },
525     { "float",       NULL,                   0,                   AV_OPT_TYPE_CONST, {.i64=EXR_FLOAT}, 0, 0, VE, "pixel" },
526     { "gamma", "set gamma", OFFSET(gamma), AV_OPT_TYPE_FLOAT, {.dbl=1.f}, 0.001, FLT_MAX, VE },
527     { NULL},
528 };
529 
530 static const AVClass exr_class = {
531     .class_name = "exr",
532     .item_name  = av_default_item_name,
533     .option     = options,
534     .version    = LIBAVUTIL_VERSION_INT,
535 };
536 
537 AVCodec ff_exr_encoder = {
538     .name           = "exr",
539     .long_name      = NULL_IF_CONFIG_SMALL("OpenEXR image"),
540     .priv_data_size = sizeof(EXRContext),
541     .priv_class     = &exr_class,
542     .type           = AVMEDIA_TYPE_VIDEO,
543     .id             = AV_CODEC_ID_EXR,
544     .init           = encode_init,
545     .encode2        = encode_frame,
546     .close          = encode_close,
547     .capabilities   = AV_CODEC_CAP_FRAME_THREADS,
548     .pix_fmts       = (const enum AVPixelFormat[]) {
549                                                  AV_PIX_FMT_GBRPF32,
550                                                  AV_PIX_FMT_GBRAPF32,
551                                                  AV_PIX_FMT_NONE },
552 };
553