xref: /third_party/ffmpeg/libavcodec/pngenc.c (revision cabdff1a)
1/*
2 * PNG image format
3 * Copyright (c) 2003 Fabrice Bellard
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#include "avcodec.h"
23#include "codec_internal.h"
24#include "encode.h"
25#include "bytestream.h"
26#include "lossless_videoencdsp.h"
27#include "png.h"
28#include "apng.h"
29#include "zlib_wrapper.h"
30
31#include "libavutil/avassert.h"
32#include "libavutil/crc.h"
33#include "libavutil/libm.h"
34#include "libavutil/opt.h"
35#include "libavutil/color_utils.h"
36#include "libavutil/stereo3d.h"
37
38#include <zlib.h>
39
40#define IOBUF_SIZE 4096
41
42typedef struct APNGFctlChunk {
43    uint32_t sequence_number;
44    uint32_t width, height;
45    uint32_t x_offset, y_offset;
46    uint16_t delay_num, delay_den;
47    uint8_t dispose_op, blend_op;
48} APNGFctlChunk;
49
50typedef struct PNGEncContext {
51    AVClass *class;
52    LLVidEncDSPContext llvidencdsp;
53
54    uint8_t *bytestream;
55    uint8_t *bytestream_start;
56    uint8_t *bytestream_end;
57
58    int filter_type;
59
60    FFZStream zstream;
61    uint8_t buf[IOBUF_SIZE];
62    int dpi;                     ///< Physical pixel density, in dots per inch, if set
63    int dpm;                     ///< Physical pixel density, in dots per meter, if set
64
65    int is_progressive;
66    int bit_depth;
67    int color_type;
68    int bits_per_pixel;
69
70    // APNG
71    uint32_t palette_checksum;   // Used to ensure a single unique palette
72    uint32_t sequence_number;
73    int extra_data_updated;
74    uint8_t *extra_data;
75    int extra_data_size;
76
77    AVFrame *prev_frame;
78    AVFrame *last_frame;
79    APNGFctlChunk last_frame_fctl;
80    uint8_t *last_frame_packet;
81    size_t last_frame_packet_size;
82} PNGEncContext;
83
84static void png_get_interlaced_row(uint8_t *dst, int row_size,
85                                   int bits_per_pixel, int pass,
86                                   const uint8_t *src, int width)
87{
88    int x, mask, dst_x, j, b, bpp;
89    uint8_t *d;
90    const uint8_t *s;
91    static const int masks[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
92
93    mask = masks[pass];
94    switch (bits_per_pixel) {
95    case 1:
96        memset(dst, 0, row_size);
97        dst_x = 0;
98        for (x = 0; x < width; x++) {
99            j = (x & 7);
100            if ((mask << j) & 0x80) {
101                b = (src[x >> 3] >> (7 - j)) & 1;
102                dst[dst_x >> 3] |= b << (7 - (dst_x & 7));
103                dst_x++;
104            }
105        }
106        break;
107    default:
108        bpp = bits_per_pixel >> 3;
109        d = dst;
110        s = src;
111        for (x = 0; x < width; x++) {
112            j = x & 7;
113            if ((mask << j) & 0x80) {
114                memcpy(d, s, bpp);
115                d += bpp;
116            }
117            s += bpp;
118        }
119        break;
120    }
121}
122
123static void sub_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top,
124                                     int w, int bpp)
125{
126    int i;
127    for (i = 0; i < w; i++) {
128        int a, b, c, p, pa, pb, pc;
129
130        a = src[i - bpp];
131        b = top[i];
132        c = top[i - bpp];
133
134        p  = b - c;
135        pc = a - c;
136
137        pa = abs(p);
138        pb = abs(pc);
139        pc = abs(p + pc);
140
141        if (pa <= pb && pa <= pc)
142            p = a;
143        else if (pb <= pc)
144            p = b;
145        else
146            p = c;
147        dst[i] = src[i] - p;
148    }
149}
150
151static void sub_left_prediction(PNGEncContext *c, uint8_t *dst, const uint8_t *src, int bpp, int size)
152{
153    const uint8_t *src1 = src + bpp;
154    const uint8_t *src2 = src;
155    int x, unaligned_w;
156
157    memcpy(dst, src, bpp);
158    dst += bpp;
159    size -= bpp;
160    unaligned_w = FFMIN(32 - bpp, size);
161    for (x = 0; x < unaligned_w; x++)
162        *dst++ = *src1++ - *src2++;
163    size -= unaligned_w;
164    c->llvidencdsp.diff_bytes(dst, src1, src2, size);
165}
166
167static void png_filter_row(PNGEncContext *c, uint8_t *dst, int filter_type,
168                           uint8_t *src, uint8_t *top, int size, int bpp)
169{
170    int i;
171
172    switch (filter_type) {
173    case PNG_FILTER_VALUE_NONE:
174        memcpy(dst, src, size);
175        break;
176    case PNG_FILTER_VALUE_SUB:
177        sub_left_prediction(c, dst, src, bpp, size);
178        break;
179    case PNG_FILTER_VALUE_UP:
180        c->llvidencdsp.diff_bytes(dst, src, top, size);
181        break;
182    case PNG_FILTER_VALUE_AVG:
183        for (i = 0; i < bpp; i++)
184            dst[i] = src[i] - (top[i] >> 1);
185        for (; i < size; i++)
186            dst[i] = src[i] - ((src[i - bpp] + top[i]) >> 1);
187        break;
188    case PNG_FILTER_VALUE_PAETH:
189        for (i = 0; i < bpp; i++)
190            dst[i] = src[i] - top[i];
191        sub_png_paeth_prediction(dst + i, src + i, top + i, size - i, bpp);
192        break;
193    }
194}
195
196static uint8_t *png_choose_filter(PNGEncContext *s, uint8_t *dst,
197                                  uint8_t *src, uint8_t *top, int size, int bpp)
198{
199    int pred = s->filter_type;
200    av_assert0(bpp || !pred);
201    if (!top && pred)
202        pred = PNG_FILTER_VALUE_SUB;
203    if (pred == PNG_FILTER_VALUE_MIXED) {
204        int i;
205        int cost, bcost = INT_MAX;
206        uint8_t *buf1 = dst, *buf2 = dst + size + 16;
207        for (pred = 0; pred < 5; pred++) {
208            png_filter_row(s, buf1 + 1, pred, src, top, size, bpp);
209            buf1[0] = pred;
210            cost = 0;
211            for (i = 0; i <= size; i++)
212                cost += abs((int8_t) buf1[i]);
213            if (cost < bcost) {
214                bcost = cost;
215                FFSWAP(uint8_t *, buf1, buf2);
216            }
217        }
218        return buf2;
219    } else {
220        png_filter_row(s, dst + 1, pred, src, top, size, bpp);
221        dst[0] = pred;
222        return dst;
223    }
224}
225
226static void png_write_chunk(uint8_t **f, uint32_t tag,
227                            const uint8_t *buf, int length)
228{
229    const AVCRC *crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
230    uint32_t crc = ~0U;
231    uint8_t tagbuf[4];
232
233    bytestream_put_be32(f, length);
234    AV_WL32(tagbuf, tag);
235    crc = av_crc(crc_table, crc, tagbuf, 4);
236    bytestream_put_be32(f, av_bswap32(tag));
237    if (length > 0) {
238        crc = av_crc(crc_table, crc, buf, length);
239        if (*f != buf)
240            memcpy(*f, buf, length);
241        *f += length;
242    }
243    bytestream_put_be32(f, ~crc);
244}
245
246static void png_write_image_data(AVCodecContext *avctx,
247                                 const uint8_t *buf, int length)
248{
249    PNGEncContext *s = avctx->priv_data;
250    const AVCRC *crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
251    uint32_t crc = ~0U;
252
253    if (avctx->codec_id == AV_CODEC_ID_PNG || avctx->frame_number == 0) {
254        png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), buf, length);
255        return;
256    }
257
258    bytestream_put_be32(&s->bytestream, length + 4);
259
260    bytestream_put_be32(&s->bytestream, MKBETAG('f', 'd', 'A', 'T'));
261    bytestream_put_be32(&s->bytestream, s->sequence_number);
262    crc = av_crc(crc_table, crc, s->bytestream - 8, 8);
263
264    crc = av_crc(crc_table, crc, buf, length);
265    memcpy(s->bytestream, buf, length);
266    s->bytestream += length;
267
268    bytestream_put_be32(&s->bytestream, ~crc);
269
270    ++s->sequence_number;
271}
272
273/* XXX: do filtering */
274static int png_write_row(AVCodecContext *avctx, const uint8_t *data, int size)
275{
276    PNGEncContext *s = avctx->priv_data;
277    z_stream *const zstream = &s->zstream.zstream;
278    int ret;
279
280    zstream->avail_in = size;
281    zstream->next_in  = data;
282    while (zstream->avail_in > 0) {
283        ret = deflate(zstream, Z_NO_FLUSH);
284        if (ret != Z_OK)
285            return -1;
286        if (zstream->avail_out == 0) {
287            if (s->bytestream_end - s->bytestream > IOBUF_SIZE + 100)
288                png_write_image_data(avctx, s->buf, IOBUF_SIZE);
289            zstream->avail_out = IOBUF_SIZE;
290            zstream->next_out  = s->buf;
291        }
292    }
293    return 0;
294}
295
296#define AV_WB32_PNG(buf, n) AV_WB32(buf, lrint((n) * 100000))
297static int png_get_chrm(enum AVColorPrimaries prim,  uint8_t *buf)
298{
299    double rx, ry, gx, gy, bx, by, wx = 0.3127, wy = 0.3290;
300    switch (prim) {
301        case AVCOL_PRI_BT709:
302            rx = 0.640; ry = 0.330;
303            gx = 0.300; gy = 0.600;
304            bx = 0.150; by = 0.060;
305            break;
306        case AVCOL_PRI_BT470M:
307            rx = 0.670; ry = 0.330;
308            gx = 0.210; gy = 0.710;
309            bx = 0.140; by = 0.080;
310            wx = 0.310; wy = 0.316;
311            break;
312        case AVCOL_PRI_BT470BG:
313            rx = 0.640; ry = 0.330;
314            gx = 0.290; gy = 0.600;
315            bx = 0.150; by = 0.060;
316            break;
317        case AVCOL_PRI_SMPTE170M:
318        case AVCOL_PRI_SMPTE240M:
319            rx = 0.630; ry = 0.340;
320            gx = 0.310; gy = 0.595;
321            bx = 0.155; by = 0.070;
322            break;
323        case AVCOL_PRI_BT2020:
324            rx = 0.708; ry = 0.292;
325            gx = 0.170; gy = 0.797;
326            bx = 0.131; by = 0.046;
327            break;
328        default:
329            return 0;
330    }
331
332    AV_WB32_PNG(buf     , wx); AV_WB32_PNG(buf + 4 , wy);
333    AV_WB32_PNG(buf + 8 , rx); AV_WB32_PNG(buf + 12, ry);
334    AV_WB32_PNG(buf + 16, gx); AV_WB32_PNG(buf + 20, gy);
335    AV_WB32_PNG(buf + 24, bx); AV_WB32_PNG(buf + 28, by);
336    return 1;
337}
338
339static int png_get_gama(enum AVColorTransferCharacteristic trc, uint8_t *buf)
340{
341    double gamma = avpriv_get_gamma_from_trc(trc);
342    if (gamma <= 1e-6)
343        return 0;
344
345    AV_WB32_PNG(buf, 1.0 / gamma);
346    return 1;
347}
348
349static int png_write_iccp(PNGEncContext *s, const AVFrameSideData *sd)
350{
351    z_stream *const zstream = &s->zstream.zstream;
352    const AVDictionaryEntry *entry;
353    const char *name;
354    uint8_t *start, *buf;
355    int ret;
356
357    if (!sd || !sd->size)
358        return 0;
359    zstream->next_in  = sd->data;
360    zstream->avail_in = sd->size;
361
362    /* write the chunk contents first */
363    start = s->bytestream + 8; /* make room for iCCP tag + length */
364    buf = start;
365
366    /* profile description */
367    entry = av_dict_get(sd->metadata, "name", NULL, 0);
368    name = (entry && entry->value[0]) ? entry->value : "icc";
369    for (int i = 0;; i++) {
370        char c = (i == 79) ? 0 : name[i];
371        bytestream_put_byte(&buf, c);
372        if (!c)
373            break;
374    }
375
376    /* compression method and profile data */
377    bytestream_put_byte(&buf, 0);
378    zstream->next_out  = buf;
379    zstream->avail_out = s->bytestream_end - buf;
380    ret = deflate(zstream, Z_FINISH);
381    deflateReset(zstream);
382    if (ret != Z_STREAM_END)
383        return AVERROR_EXTERNAL;
384
385    /* rewind to the start and write the chunk header/crc */
386    png_write_chunk(&s->bytestream, MKTAG('i', 'C', 'C', 'P'), start,
387                    zstream->next_out - start);
388    return 0;
389}
390
391static int encode_headers(AVCodecContext *avctx, const AVFrame *pict)
392{
393    AVFrameSideData *side_data;
394    PNGEncContext *s = avctx->priv_data;
395    int ret;
396
397    /* write png header */
398    AV_WB32(s->buf, avctx->width);
399    AV_WB32(s->buf + 4, avctx->height);
400    s->buf[8]  = s->bit_depth;
401    s->buf[9]  = s->color_type;
402    s->buf[10] = 0; /* compression type */
403    s->buf[11] = 0; /* filter type */
404    s->buf[12] = s->is_progressive; /* interlace type */
405    png_write_chunk(&s->bytestream, MKTAG('I', 'H', 'D', 'R'), s->buf, 13);
406
407    /* write physical information */
408    if (s->dpm) {
409      AV_WB32(s->buf, s->dpm);
410      AV_WB32(s->buf + 4, s->dpm);
411      s->buf[8] = 1; /* unit specifier is meter */
412    } else {
413      AV_WB32(s->buf, avctx->sample_aspect_ratio.num);
414      AV_WB32(s->buf + 4, avctx->sample_aspect_ratio.den);
415      s->buf[8] = 0; /* unit specifier is unknown */
416    }
417    png_write_chunk(&s->bytestream, MKTAG('p', 'H', 'Y', 's'), s->buf, 9);
418
419    /* write stereoscopic information */
420    side_data = av_frame_get_side_data(pict, AV_FRAME_DATA_STEREO3D);
421    if (side_data) {
422        AVStereo3D *stereo3d = (AVStereo3D *)side_data->data;
423        switch (stereo3d->type) {
424            case AV_STEREO3D_SIDEBYSIDE:
425                s->buf[0] = ((stereo3d->flags & AV_STEREO3D_FLAG_INVERT) == 0) ? 1 : 0;
426                png_write_chunk(&s->bytestream, MKTAG('s', 'T', 'E', 'R'), s->buf, 1);
427                break;
428            case AV_STEREO3D_2D:
429                break;
430            default:
431                av_log(avctx, AV_LOG_WARNING, "Only side-by-side stereo3d flag can be defined within sTER chunk\n");
432                break;
433        }
434    }
435
436    /* write colorspace information */
437    if (pict->color_primaries == AVCOL_PRI_BT709 &&
438        pict->color_trc == AVCOL_TRC_IEC61966_2_1) {
439        s->buf[0] = 1; /* rendering intent, relative colorimetric by default */
440        png_write_chunk(&s->bytestream, MKTAG('s', 'R', 'G', 'B'), s->buf, 1);
441    }
442
443    if (png_get_chrm(pict->color_primaries, s->buf))
444        png_write_chunk(&s->bytestream, MKTAG('c', 'H', 'R', 'M'), s->buf, 32);
445    if (png_get_gama(pict->color_trc, s->buf))
446        png_write_chunk(&s->bytestream, MKTAG('g', 'A', 'M', 'A'), s->buf, 4);
447
448    side_data = av_frame_get_side_data(pict, AV_FRAME_DATA_ICC_PROFILE);
449    if ((ret = png_write_iccp(s, side_data)))
450        return ret;
451
452    /* put the palette if needed, must be after colorspace information */
453    if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
454        int has_alpha, alpha, i;
455        unsigned int v;
456        uint32_t *palette;
457        uint8_t *ptr, *alpha_ptr;
458
459        palette   = (uint32_t *)pict->data[1];
460        ptr       = s->buf;
461        alpha_ptr = s->buf + 256 * 3;
462        has_alpha = 0;
463        for (i = 0; i < 256; i++) {
464            v     = palette[i];
465            alpha = v >> 24;
466            if (alpha != 0xff)
467                has_alpha = 1;
468            *alpha_ptr++ = alpha;
469            bytestream_put_be24(&ptr, v);
470        }
471        png_write_chunk(&s->bytestream,
472                        MKTAG('P', 'L', 'T', 'E'), s->buf, 256 * 3);
473        if (has_alpha) {
474            png_write_chunk(&s->bytestream,
475                            MKTAG('t', 'R', 'N', 'S'), s->buf + 256 * 3, 256);
476        }
477    }
478
479    return 0;
480}
481
482static int encode_frame(AVCodecContext *avctx, const AVFrame *pict)
483{
484    PNGEncContext *s       = avctx->priv_data;
485    z_stream *const zstream = &s->zstream.zstream;
486    const AVFrame *const p = pict;
487    int y, len, ret;
488    int row_size, pass_row_size;
489    uint8_t *ptr, *top, *crow_buf, *crow;
490    uint8_t *crow_base       = NULL;
491    uint8_t *progressive_buf = NULL;
492    uint8_t *top_buf         = NULL;
493
494    row_size = (pict->width * s->bits_per_pixel + 7) >> 3;
495
496    crow_base = av_malloc((row_size + 32) << (s->filter_type == PNG_FILTER_VALUE_MIXED));
497    if (!crow_base) {
498        ret = AVERROR(ENOMEM);
499        goto the_end;
500    }
501    // pixel data should be aligned, but there's a control byte before it
502    crow_buf = crow_base + 15;
503    if (s->is_progressive) {
504        progressive_buf = av_malloc(row_size + 1);
505        top_buf = av_malloc(row_size + 1);
506        if (!progressive_buf || !top_buf) {
507            ret = AVERROR(ENOMEM);
508            goto the_end;
509        }
510    }
511
512    /* put each row */
513    zstream->avail_out = IOBUF_SIZE;
514    zstream->next_out  = s->buf;
515    if (s->is_progressive) {
516        int pass;
517
518        for (pass = 0; pass < NB_PASSES; pass++) {
519            /* NOTE: a pass is completely omitted if no pixels would be
520             * output */
521            pass_row_size = ff_png_pass_row_size(pass, s->bits_per_pixel, pict->width);
522            if (pass_row_size > 0) {
523                top = NULL;
524                for (y = 0; y < pict->height; y++)
525                    if ((ff_png_pass_ymask[pass] << (y & 7)) & 0x80) {
526                        ptr = p->data[0] + y * p->linesize[0];
527                        FFSWAP(uint8_t *, progressive_buf, top_buf);
528                        png_get_interlaced_row(progressive_buf, pass_row_size,
529                                               s->bits_per_pixel, pass,
530                                               ptr, pict->width);
531                        crow = png_choose_filter(s, crow_buf, progressive_buf,
532                                                 top, pass_row_size, s->bits_per_pixel >> 3);
533                        png_write_row(avctx, crow, pass_row_size + 1);
534                        top = progressive_buf;
535                    }
536            }
537        }
538    } else {
539        top = NULL;
540        for (y = 0; y < pict->height; y++) {
541            ptr = p->data[0] + y * p->linesize[0];
542            crow = png_choose_filter(s, crow_buf, ptr, top,
543                                     row_size, s->bits_per_pixel >> 3);
544            png_write_row(avctx, crow, row_size + 1);
545            top = ptr;
546        }
547    }
548    /* compress last bytes */
549    for (;;) {
550        ret = deflate(zstream, Z_FINISH);
551        if (ret == Z_OK || ret == Z_STREAM_END) {
552            len = IOBUF_SIZE - zstream->avail_out;
553            if (len > 0 && s->bytestream_end - s->bytestream > len + 100) {
554                png_write_image_data(avctx, s->buf, len);
555            }
556            zstream->avail_out = IOBUF_SIZE;
557            zstream->next_out  = s->buf;
558            if (ret == Z_STREAM_END)
559                break;
560        } else {
561            ret = -1;
562            goto the_end;
563        }
564    }
565
566    ret = 0;
567
568the_end:
569    av_freep(&crow_base);
570    av_freep(&progressive_buf);
571    av_freep(&top_buf);
572    deflateReset(zstream);
573    return ret;
574}
575
576static int add_icc_profile_size(AVCodecContext *avctx, const AVFrame *pict,
577                                uint64_t *max_packet_size)
578{
579    PNGEncContext *s = avctx->priv_data;
580    const AVFrameSideData *sd;
581    const int hdr_size = 128;
582    uint64_t new_pkt_size;
583    uLong bound;
584
585    if (!pict)
586        return 0;
587    sd = av_frame_get_side_data(pict, AV_FRAME_DATA_ICC_PROFILE);
588    if (!sd || !sd->size)
589        return 0;
590    if (sd->size != (uLong) sd->size)
591        return AVERROR_INVALIDDATA;
592
593    bound = deflateBound(&s->zstream.zstream, sd->size);
594    if (bound > INT32_MAX - hdr_size)
595        return AVERROR_INVALIDDATA;
596
597    new_pkt_size = *max_packet_size + bound + hdr_size;
598    if (new_pkt_size < *max_packet_size)
599        return AVERROR_INVALIDDATA;
600    *max_packet_size = new_pkt_size;
601    return 0;
602}
603
604static int encode_png(AVCodecContext *avctx, AVPacket *pkt,
605                      const AVFrame *pict, int *got_packet)
606{
607    PNGEncContext *s = avctx->priv_data;
608    int ret;
609    int enc_row_size;
610    uint64_t max_packet_size;
611
612    enc_row_size    = deflateBound(&s->zstream.zstream,
613                                   (avctx->width * s->bits_per_pixel + 7) >> 3);
614    max_packet_size =
615        AV_INPUT_BUFFER_MIN_SIZE + // headers
616        avctx->height * (
617            enc_row_size +
618            12 * (((int64_t)enc_row_size + IOBUF_SIZE - 1) / IOBUF_SIZE) // IDAT * ceil(enc_row_size / IOBUF_SIZE)
619        );
620    if ((ret = add_icc_profile_size(avctx, pict, &max_packet_size)))
621        return ret;
622    ret = ff_alloc_packet(avctx, pkt, max_packet_size);
623    if (ret < 0)
624        return ret;
625
626    s->bytestream_start =
627    s->bytestream       = pkt->data;
628    s->bytestream_end   = pkt->data + pkt->size;
629
630    AV_WB64(s->bytestream, PNGSIG);
631    s->bytestream += 8;
632
633    ret = encode_headers(avctx, pict);
634    if (ret < 0)
635        return ret;
636
637    ret = encode_frame(avctx, pict);
638    if (ret < 0)
639        return ret;
640
641    png_write_chunk(&s->bytestream, MKTAG('I', 'E', 'N', 'D'), NULL, 0);
642
643    pkt->size = s->bytestream - s->bytestream_start;
644    pkt->flags |= AV_PKT_FLAG_KEY;
645    *got_packet = 1;
646
647    return 0;
648}
649
650static int apng_do_inverse_blend(AVFrame *output, const AVFrame *input,
651                                  APNGFctlChunk *fctl_chunk, uint8_t bpp)
652{
653    // output: background, input: foreground
654    // output the image such that when blended with the background, will produce the foreground
655
656    unsigned int x, y;
657    unsigned int leftmost_x = input->width;
658    unsigned int rightmost_x = 0;
659    unsigned int topmost_y = input->height;
660    unsigned int bottommost_y = 0;
661    const uint8_t *input_data = input->data[0];
662    uint8_t *output_data = output->data[0];
663    ptrdiff_t input_linesize = input->linesize[0];
664    ptrdiff_t output_linesize = output->linesize[0];
665
666    // Find bounding box of changes
667    for (y = 0; y < input->height; ++y) {
668        for (x = 0; x < input->width; ++x) {
669            if (!memcmp(input_data + bpp * x, output_data + bpp * x, bpp))
670                continue;
671
672            if (x < leftmost_x)
673                leftmost_x = x;
674            if (x >= rightmost_x)
675                rightmost_x = x + 1;
676            if (y < topmost_y)
677                topmost_y = y;
678            if (y >= bottommost_y)
679                bottommost_y = y + 1;
680        }
681
682        input_data += input_linesize;
683        output_data += output_linesize;
684    }
685
686    if (leftmost_x == input->width && rightmost_x == 0) {
687        // Empty frame
688        // APNG does not support empty frames, so we make it a 1x1 frame
689        leftmost_x = topmost_y = 0;
690        rightmost_x = bottommost_y = 1;
691    }
692
693    // Do actual inverse blending
694    if (fctl_chunk->blend_op == APNG_BLEND_OP_SOURCE) {
695        output_data = output->data[0];
696        for (y = topmost_y; y < bottommost_y; ++y) {
697            memcpy(output_data,
698                   input->data[0] + input_linesize * y + bpp * leftmost_x,
699                   bpp * (rightmost_x - leftmost_x));
700            output_data += output_linesize;
701        }
702    } else { // APNG_BLEND_OP_OVER
703        size_t transparent_palette_index;
704        uint32_t *palette;
705
706        switch (input->format) {
707        case AV_PIX_FMT_RGBA64BE:
708        case AV_PIX_FMT_YA16BE:
709        case AV_PIX_FMT_RGBA:
710        case AV_PIX_FMT_GRAY8A:
711            break;
712
713        case AV_PIX_FMT_PAL8:
714            palette = (uint32_t*)input->data[1];
715            for (transparent_palette_index = 0; transparent_palette_index < 256; ++transparent_palette_index)
716                if (palette[transparent_palette_index] >> 24 == 0)
717                    break;
718            break;
719
720        default:
721            // No alpha, so blending not possible
722            return -1;
723        }
724
725        for (y = topmost_y; y < bottommost_y; ++y) {
726            uint8_t *foreground = input->data[0] + input_linesize * y + bpp * leftmost_x;
727            uint8_t *background = output->data[0] + output_linesize * y + bpp * leftmost_x;
728            output_data = output->data[0] + output_linesize * (y - topmost_y);
729            for (x = leftmost_x; x < rightmost_x; ++x, foreground += bpp, background += bpp, output_data += bpp) {
730                if (!memcmp(foreground, background, bpp)) {
731                    if (input->format == AV_PIX_FMT_PAL8) {
732                        if (transparent_palette_index == 256) {
733                            // Need fully transparent colour, but none exists
734                            return -1;
735                        }
736
737                        *output_data = transparent_palette_index;
738                    } else {
739                        memset(output_data, 0, bpp);
740                    }
741                    continue;
742                }
743
744                // Check for special alpha values, since full inverse
745                // alpha-on-alpha blending is rarely possible, and when
746                // possible, doesn't compress much better than
747                // APNG_BLEND_OP_SOURCE blending
748                switch (input->format) {
749                case AV_PIX_FMT_RGBA64BE:
750                    if (((uint16_t*)foreground)[3] == 0xffff ||
751                        ((uint16_t*)background)[3] == 0)
752                        break;
753                    return -1;
754
755                case AV_PIX_FMT_YA16BE:
756                    if (((uint16_t*)foreground)[1] == 0xffff ||
757                        ((uint16_t*)background)[1] == 0)
758                        break;
759                    return -1;
760
761                case AV_PIX_FMT_RGBA:
762                    if (foreground[3] == 0xff || background[3] == 0)
763                        break;
764                    return -1;
765
766                case AV_PIX_FMT_GRAY8A:
767                    if (foreground[1] == 0xff || background[1] == 0)
768                        break;
769                    return -1;
770
771                case AV_PIX_FMT_PAL8:
772                    if (palette[*foreground] >> 24 == 0xff ||
773                        palette[*background] >> 24 == 0)
774                        break;
775                    return -1;
776                }
777
778                memmove(output_data, foreground, bpp);
779            }
780        }
781    }
782
783    output->width = rightmost_x - leftmost_x;
784    output->height = bottommost_y - topmost_y;
785    fctl_chunk->width = output->width;
786    fctl_chunk->height = output->height;
787    fctl_chunk->x_offset = leftmost_x;
788    fctl_chunk->y_offset = topmost_y;
789
790    return 0;
791}
792
793static int apng_encode_frame(AVCodecContext *avctx, const AVFrame *pict,
794                             APNGFctlChunk *best_fctl_chunk, APNGFctlChunk *best_last_fctl_chunk)
795{
796    PNGEncContext *s = avctx->priv_data;
797    int ret;
798    unsigned int y;
799    AVFrame* diffFrame;
800    uint8_t bpp = (s->bits_per_pixel + 7) >> 3;
801    uint8_t *original_bytestream, *original_bytestream_end;
802    uint8_t *temp_bytestream = 0, *temp_bytestream_end;
803    uint32_t best_sequence_number;
804    uint8_t *best_bytestream;
805    size_t best_bytestream_size = SIZE_MAX;
806    APNGFctlChunk last_fctl_chunk = *best_last_fctl_chunk;
807    APNGFctlChunk fctl_chunk = *best_fctl_chunk;
808
809    if (avctx->frame_number == 0) {
810        best_fctl_chunk->width = pict->width;
811        best_fctl_chunk->height = pict->height;
812        best_fctl_chunk->x_offset = 0;
813        best_fctl_chunk->y_offset = 0;
814        best_fctl_chunk->blend_op = APNG_BLEND_OP_SOURCE;
815        return encode_frame(avctx, pict);
816    }
817
818    diffFrame = av_frame_alloc();
819    if (!diffFrame)
820        return AVERROR(ENOMEM);
821
822    diffFrame->format = pict->format;
823    diffFrame->width = pict->width;
824    diffFrame->height = pict->height;
825    if ((ret = av_frame_get_buffer(diffFrame, 0)) < 0)
826        goto fail;
827
828    original_bytestream = s->bytestream;
829    original_bytestream_end = s->bytestream_end;
830
831    temp_bytestream = av_malloc(original_bytestream_end - original_bytestream);
832    if (!temp_bytestream) {
833        ret = AVERROR(ENOMEM);
834        goto fail;
835    }
836    temp_bytestream_end = temp_bytestream + (original_bytestream_end - original_bytestream);
837
838    for (last_fctl_chunk.dispose_op = 0; last_fctl_chunk.dispose_op < 3; ++last_fctl_chunk.dispose_op) {
839        // 0: APNG_DISPOSE_OP_NONE
840        // 1: APNG_DISPOSE_OP_BACKGROUND
841        // 2: APNG_DISPOSE_OP_PREVIOUS
842
843        for (fctl_chunk.blend_op = 0; fctl_chunk.blend_op < 2; ++fctl_chunk.blend_op) {
844            // 0: APNG_BLEND_OP_SOURCE
845            // 1: APNG_BLEND_OP_OVER
846
847            uint32_t original_sequence_number = s->sequence_number, sequence_number;
848            uint8_t *bytestream_start = s->bytestream;
849            size_t bytestream_size;
850
851            // Do disposal
852            if (last_fctl_chunk.dispose_op != APNG_DISPOSE_OP_PREVIOUS) {
853                diffFrame->width = pict->width;
854                diffFrame->height = pict->height;
855                ret = av_frame_copy(diffFrame, s->last_frame);
856                if (ret < 0)
857                    goto fail;
858
859                if (last_fctl_chunk.dispose_op == APNG_DISPOSE_OP_BACKGROUND) {
860                    for (y = last_fctl_chunk.y_offset; y < last_fctl_chunk.y_offset + last_fctl_chunk.height; ++y) {
861                        size_t row_start = diffFrame->linesize[0] * y + bpp * last_fctl_chunk.x_offset;
862                        memset(diffFrame->data[0] + row_start, 0, bpp * last_fctl_chunk.width);
863                    }
864                }
865            } else {
866                if (!s->prev_frame)
867                    continue;
868
869                diffFrame->width = pict->width;
870                diffFrame->height = pict->height;
871                ret = av_frame_copy(diffFrame, s->prev_frame);
872                if (ret < 0)
873                    goto fail;
874            }
875
876            // Do inverse blending
877            if (apng_do_inverse_blend(diffFrame, pict, &fctl_chunk, bpp) < 0)
878                continue;
879
880            // Do encoding
881            ret = encode_frame(avctx, diffFrame);
882            sequence_number = s->sequence_number;
883            s->sequence_number = original_sequence_number;
884            bytestream_size = s->bytestream - bytestream_start;
885            s->bytestream = bytestream_start;
886            if (ret < 0)
887                goto fail;
888
889            if (bytestream_size < best_bytestream_size) {
890                *best_fctl_chunk = fctl_chunk;
891                *best_last_fctl_chunk = last_fctl_chunk;
892
893                best_sequence_number = sequence_number;
894                best_bytestream = s->bytestream;
895                best_bytestream_size = bytestream_size;
896
897                if (best_bytestream == original_bytestream) {
898                    s->bytestream = temp_bytestream;
899                    s->bytestream_end = temp_bytestream_end;
900                } else {
901                    s->bytestream = original_bytestream;
902                    s->bytestream_end = original_bytestream_end;
903                }
904            }
905        }
906    }
907
908    s->sequence_number = best_sequence_number;
909    s->bytestream = original_bytestream + best_bytestream_size;
910    s->bytestream_end = original_bytestream_end;
911    if (best_bytestream != original_bytestream)
912        memcpy(original_bytestream, best_bytestream, best_bytestream_size);
913
914    ret = 0;
915
916fail:
917    av_freep(&temp_bytestream);
918    av_frame_free(&diffFrame);
919    return ret;
920}
921
922static int encode_apng(AVCodecContext *avctx, AVPacket *pkt,
923                       const AVFrame *pict, int *got_packet)
924{
925    PNGEncContext *s = avctx->priv_data;
926    int ret;
927    int enc_row_size;
928    uint64_t max_packet_size;
929    APNGFctlChunk fctl_chunk = {0};
930
931    if (pict && s->color_type == PNG_COLOR_TYPE_PALETTE) {
932        uint32_t checksum = ~av_crc(av_crc_get_table(AV_CRC_32_IEEE_LE), ~0U, pict->data[1], 256 * sizeof(uint32_t));
933
934        if (avctx->frame_number == 0) {
935            s->palette_checksum = checksum;
936        } else if (checksum != s->palette_checksum) {
937            av_log(avctx, AV_LOG_ERROR,
938                   "Input contains more than one unique palette. APNG does not support multiple palettes.\n");
939            return -1;
940        }
941    }
942
943    enc_row_size    = deflateBound(&s->zstream.zstream,
944                                   (avctx->width * s->bits_per_pixel + 7) >> 3);
945    max_packet_size =
946        AV_INPUT_BUFFER_MIN_SIZE + // headers
947        avctx->height * (
948            enc_row_size +
949            (4 + 12) * (((int64_t)enc_row_size + IOBUF_SIZE - 1) / IOBUF_SIZE) // fdAT * ceil(enc_row_size / IOBUF_SIZE)
950        );
951    if ((ret = add_icc_profile_size(avctx, pict, &max_packet_size)))
952        return ret;
953    if (max_packet_size > INT_MAX)
954        return AVERROR(ENOMEM);
955
956    if (avctx->frame_number == 0) {
957        if (!pict)
958            return AVERROR(EINVAL);
959
960        s->bytestream = s->extra_data = av_malloc(AV_INPUT_BUFFER_MIN_SIZE);
961        if (!s->extra_data)
962            return AVERROR(ENOMEM);
963
964        ret = encode_headers(avctx, pict);
965        if (ret < 0)
966            return ret;
967
968        s->extra_data_size = s->bytestream - s->extra_data;
969
970        s->last_frame_packet = av_malloc(max_packet_size);
971        if (!s->last_frame_packet)
972            return AVERROR(ENOMEM);
973    } else if (s->last_frame) {
974        ret = ff_get_encode_buffer(avctx, pkt, s->last_frame_packet_size, 0);
975        if (ret < 0)
976            return ret;
977
978        memcpy(pkt->data, s->last_frame_packet, s->last_frame_packet_size);
979        pkt->pts = pkt->dts = s->last_frame->pts;
980    }
981
982    if (pict) {
983        s->bytestream_start =
984        s->bytestream       = s->last_frame_packet;
985        s->bytestream_end   = s->bytestream + max_packet_size;
986
987        // We're encoding the frame first, so we have to do a bit of shuffling around
988        // to have the image data write to the correct place in the buffer
989        fctl_chunk.sequence_number = s->sequence_number;
990        ++s->sequence_number;
991        s->bytestream += APNG_FCTL_CHUNK_SIZE + 12;
992
993        ret = apng_encode_frame(avctx, pict, &fctl_chunk, &s->last_frame_fctl);
994        if (ret < 0)
995            return ret;
996
997        fctl_chunk.delay_num = 0; // delay filled in during muxing
998        fctl_chunk.delay_den = 0;
999    } else {
1000        s->last_frame_fctl.dispose_op = APNG_DISPOSE_OP_NONE;
1001    }
1002
1003    if (s->last_frame) {
1004        uint8_t* last_fctl_chunk_start = pkt->data;
1005        uint8_t buf[APNG_FCTL_CHUNK_SIZE];
1006        if (!s->extra_data_updated) {
1007            uint8_t *side_data = av_packet_new_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, s->extra_data_size);
1008            if (!side_data)
1009                return AVERROR(ENOMEM);
1010            memcpy(side_data, s->extra_data, s->extra_data_size);
1011            s->extra_data_updated = 1;
1012        }
1013
1014        AV_WB32(buf + 0, s->last_frame_fctl.sequence_number);
1015        AV_WB32(buf + 4, s->last_frame_fctl.width);
1016        AV_WB32(buf + 8, s->last_frame_fctl.height);
1017        AV_WB32(buf + 12, s->last_frame_fctl.x_offset);
1018        AV_WB32(buf + 16, s->last_frame_fctl.y_offset);
1019        AV_WB16(buf + 20, s->last_frame_fctl.delay_num);
1020        AV_WB16(buf + 22, s->last_frame_fctl.delay_den);
1021        buf[24] = s->last_frame_fctl.dispose_op;
1022        buf[25] = s->last_frame_fctl.blend_op;
1023        png_write_chunk(&last_fctl_chunk_start, MKTAG('f', 'c', 'T', 'L'), buf, sizeof(buf));
1024
1025        *got_packet = 1;
1026    }
1027
1028    if (pict) {
1029        if (!s->last_frame) {
1030            s->last_frame = av_frame_alloc();
1031            if (!s->last_frame)
1032                return AVERROR(ENOMEM);
1033        } else if (s->last_frame_fctl.dispose_op != APNG_DISPOSE_OP_PREVIOUS) {
1034            if (!s->prev_frame) {
1035                s->prev_frame = av_frame_alloc();
1036                if (!s->prev_frame)
1037                    return AVERROR(ENOMEM);
1038
1039                s->prev_frame->format = pict->format;
1040                s->prev_frame->width = pict->width;
1041                s->prev_frame->height = pict->height;
1042                if ((ret = av_frame_get_buffer(s->prev_frame, 0)) < 0)
1043                    return ret;
1044            }
1045
1046            // Do disposal, but not blending
1047            av_frame_copy(s->prev_frame, s->last_frame);
1048            if (s->last_frame_fctl.dispose_op == APNG_DISPOSE_OP_BACKGROUND) {
1049                uint32_t y;
1050                uint8_t bpp = (s->bits_per_pixel + 7) >> 3;
1051                for (y = s->last_frame_fctl.y_offset; y < s->last_frame_fctl.y_offset + s->last_frame_fctl.height; ++y) {
1052                    size_t row_start = s->prev_frame->linesize[0] * y + bpp * s->last_frame_fctl.x_offset;
1053                    memset(s->prev_frame->data[0] + row_start, 0, bpp * s->last_frame_fctl.width);
1054                }
1055            }
1056        }
1057
1058        av_frame_unref(s->last_frame);
1059        ret = av_frame_ref(s->last_frame, (AVFrame*)pict);
1060        if (ret < 0)
1061            return ret;
1062
1063        s->last_frame_fctl = fctl_chunk;
1064        s->last_frame_packet_size = s->bytestream - s->bytestream_start;
1065    } else {
1066        av_frame_free(&s->last_frame);
1067    }
1068
1069    return 0;
1070}
1071
1072static av_cold int png_enc_init(AVCodecContext *avctx)
1073{
1074    PNGEncContext *s = avctx->priv_data;
1075    int compression_level;
1076
1077    switch (avctx->pix_fmt) {
1078    case AV_PIX_FMT_RGBA:
1079        avctx->bits_per_coded_sample = 32;
1080        break;
1081    case AV_PIX_FMT_RGB24:
1082        avctx->bits_per_coded_sample = 24;
1083        break;
1084    case AV_PIX_FMT_GRAY8:
1085        avctx->bits_per_coded_sample = 0x28;
1086        break;
1087    case AV_PIX_FMT_MONOBLACK:
1088        avctx->bits_per_coded_sample = 1;
1089        break;
1090    case AV_PIX_FMT_PAL8:
1091        avctx->bits_per_coded_sample = 8;
1092    }
1093
1094    ff_llvidencdsp_init(&s->llvidencdsp);
1095
1096    if (avctx->pix_fmt == AV_PIX_FMT_MONOBLACK)
1097        s->filter_type = PNG_FILTER_VALUE_NONE;
1098
1099    if (s->dpi && s->dpm) {
1100      av_log(avctx, AV_LOG_ERROR, "Only one of 'dpi' or 'dpm' options should be set\n");
1101      return AVERROR(EINVAL);
1102    } else if (s->dpi) {
1103      s->dpm = s->dpi * 10000 / 254;
1104    }
1105
1106    s->is_progressive = !!(avctx->flags & AV_CODEC_FLAG_INTERLACED_DCT);
1107    switch (avctx->pix_fmt) {
1108    case AV_PIX_FMT_RGBA64BE:
1109        s->bit_depth = 16;
1110        s->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
1111        break;
1112    case AV_PIX_FMT_RGB48BE:
1113        s->bit_depth = 16;
1114        s->color_type = PNG_COLOR_TYPE_RGB;
1115        break;
1116    case AV_PIX_FMT_RGBA:
1117        s->bit_depth  = 8;
1118        s->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
1119        break;
1120    case AV_PIX_FMT_RGB24:
1121        s->bit_depth  = 8;
1122        s->color_type = PNG_COLOR_TYPE_RGB;
1123        break;
1124    case AV_PIX_FMT_GRAY16BE:
1125        s->bit_depth  = 16;
1126        s->color_type = PNG_COLOR_TYPE_GRAY;
1127        break;
1128    case AV_PIX_FMT_GRAY8:
1129        s->bit_depth  = 8;
1130        s->color_type = PNG_COLOR_TYPE_GRAY;
1131        break;
1132    case AV_PIX_FMT_GRAY8A:
1133        s->bit_depth = 8;
1134        s->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
1135        break;
1136    case AV_PIX_FMT_YA16BE:
1137        s->bit_depth = 16;
1138        s->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
1139        break;
1140    case AV_PIX_FMT_MONOBLACK:
1141        s->bit_depth  = 1;
1142        s->color_type = PNG_COLOR_TYPE_GRAY;
1143        break;
1144    case AV_PIX_FMT_PAL8:
1145        s->bit_depth  = 8;
1146        s->color_type = PNG_COLOR_TYPE_PALETTE;
1147        break;
1148    default:
1149        return -1;
1150    }
1151    s->bits_per_pixel = ff_png_get_nb_channels(s->color_type) * s->bit_depth;
1152
1153    compression_level = avctx->compression_level == FF_COMPRESSION_DEFAULT
1154                      ? Z_DEFAULT_COMPRESSION
1155                      : av_clip(avctx->compression_level, 0, 9);
1156    return ff_deflate_init(&s->zstream, compression_level, avctx);
1157}
1158
1159static av_cold int png_enc_close(AVCodecContext *avctx)
1160{
1161    PNGEncContext *s = avctx->priv_data;
1162
1163    ff_deflate_end(&s->zstream);
1164    av_frame_free(&s->last_frame);
1165    av_frame_free(&s->prev_frame);
1166    av_freep(&s->last_frame_packet);
1167    av_freep(&s->extra_data);
1168    s->extra_data_size = 0;
1169    return 0;
1170}
1171
1172#define OFFSET(x) offsetof(PNGEncContext, x)
1173#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
1174static const AVOption options[] = {
1175    {"dpi", "Set image resolution (in dots per inch)",  OFFSET(dpi), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 0x10000, VE},
1176    {"dpm", "Set image resolution (in dots per meter)", OFFSET(dpm), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 0x10000, VE},
1177    { "pred", "Prediction method", OFFSET(filter_type), AV_OPT_TYPE_INT, { .i64 = PNG_FILTER_VALUE_NONE }, PNG_FILTER_VALUE_NONE, PNG_FILTER_VALUE_MIXED, VE, "pred" },
1178        { "none",  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PNG_FILTER_VALUE_NONE },  INT_MIN, INT_MAX, VE, "pred" },
1179        { "sub",   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PNG_FILTER_VALUE_SUB },   INT_MIN, INT_MAX, VE, "pred" },
1180        { "up",    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PNG_FILTER_VALUE_UP },    INT_MIN, INT_MAX, VE, "pred" },
1181        { "avg",   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PNG_FILTER_VALUE_AVG },   INT_MIN, INT_MAX, VE, "pred" },
1182        { "paeth", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PNG_FILTER_VALUE_PAETH }, INT_MIN, INT_MAX, VE, "pred" },
1183        { "mixed", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PNG_FILTER_VALUE_MIXED }, INT_MIN, INT_MAX, VE, "pred" },
1184    { NULL},
1185};
1186
1187static const AVClass pngenc_class = {
1188    .class_name = "(A)PNG encoder",
1189    .item_name  = av_default_item_name,
1190    .option     = options,
1191    .version    = LIBAVUTIL_VERSION_INT,
1192};
1193
1194const FFCodec ff_png_encoder = {
1195    .p.name         = "png",
1196    .p.long_name    = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),
1197    .p.type         = AVMEDIA_TYPE_VIDEO,
1198    .p.id           = AV_CODEC_ID_PNG,
1199    .priv_data_size = sizeof(PNGEncContext),
1200    .init           = png_enc_init,
1201    .close          = png_enc_close,
1202    FF_CODEC_ENCODE_CB(encode_png),
1203    .p.capabilities = AV_CODEC_CAP_FRAME_THREADS,
1204    .p.pix_fmts     = (const enum AVPixelFormat[]) {
1205        AV_PIX_FMT_RGB24, AV_PIX_FMT_RGBA,
1206        AV_PIX_FMT_RGB48BE, AV_PIX_FMT_RGBA64BE,
1207        AV_PIX_FMT_PAL8,
1208        AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY8A,
1209        AV_PIX_FMT_GRAY16BE, AV_PIX_FMT_YA16BE,
1210        AV_PIX_FMT_MONOBLACK, AV_PIX_FMT_NONE
1211    },
1212    .p.priv_class   = &pngenc_class,
1213    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
1214};
1215
1216const FFCodec ff_apng_encoder = {
1217    .p.name         = "apng",
1218    .p.long_name    = NULL_IF_CONFIG_SMALL("APNG (Animated Portable Network Graphics) image"),
1219    .p.type         = AVMEDIA_TYPE_VIDEO,
1220    .p.id           = AV_CODEC_ID_APNG,
1221    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
1222    .priv_data_size = sizeof(PNGEncContext),
1223    .init           = png_enc_init,
1224    .close          = png_enc_close,
1225    FF_CODEC_ENCODE_CB(encode_apng),
1226    .p.pix_fmts     = (const enum AVPixelFormat[]) {
1227        AV_PIX_FMT_RGB24, AV_PIX_FMT_RGBA,
1228        AV_PIX_FMT_RGB48BE, AV_PIX_FMT_RGBA64BE,
1229        AV_PIX_FMT_PAL8,
1230        AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY8A,
1231        AV_PIX_FMT_GRAY16BE, AV_PIX_FMT_YA16BE,
1232        AV_PIX_FMT_NONE
1233    },
1234    .p.priv_class   = &pngenc_class,
1235    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
1236};
1237