pngdec.c 31.8 KB
Newer Older
1 2
/*
 * PNG image format
3
 * Copyright (c) 2003 Fabrice Bellard
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
21 22 23

//#define DEBUG

24
#include "libavutil/bprint.h"
25
#include "libavutil/imgutils.h"
26 27
#include "avcodec.h"
#include "bytestream.h"
28
#include "internal.h"
29
#include "png.h"
30
#include "pngdsp.h"
31
#include "thread.h"
32 33 34

#include <zlib.h>

35
typedef struct PNGDecContext {
36
    PNGDSPContext dsp;
37
    AVCodecContext *avctx;
38

39
    GetByteContext gb;
40 41
    ThreadFrame last_picture;
    ThreadFrame picture;
42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58

    int state;
    int width, height;
    int bit_depth;
    int color_type;
    int compression_type;
    int interlace_type;
    int filter_type;
    int channels;
    int bits_per_pixel;
    int bpp;

    uint8_t *image_buf;
    int image_linesize;
    uint32_t palette[256];
    uint8_t *crow_buf;
    uint8_t *last_row;
59
    unsigned int last_row_size;
60
    uint8_t *tmp_row;
61
    unsigned int tmp_row_size;
62 63
    uint8_t *buffer;
    int buffer_size;
64 65 66 67 68 69 70 71
    int pass;
    int crow_size; /* compressed row size (include filter type) */
    int row_size; /* decompressed row size */
    int pass_row_size; /* decompress row size of the current pass */
    int y;
    z_stream zstream;
} PNGDecContext;

72 73 74 75 76
/* Mask to determine which pixels are valid in a pass */
static const uint8_t png_pass_mask[NB_PASSES] = {
    0x01, 0x01, 0x11, 0x11, 0x55, 0x55, 0xff,
};

77 78
/* Mask to determine which y pixels can be written in a pass */
static const uint8_t png_pass_dsp_ymask[NB_PASSES] = {
79
    0xff, 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
80 81 82 83 84 85 86 87
};

/* Mask to determine which pixels to overwrite while displaying */
static const uint8_t png_pass_dsp_mask[NB_PASSES] = {
    0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff
};

/* NOTE: we try to construct a good looking image at each pass. width
Diego Biurrun's avatar
Diego Biurrun committed
88
   is the original image width. We also do pixel format conversion at
89 90 91 92 93 94 95 96 97
   this stage */
static void png_put_interlaced_row(uint8_t *dst, int width,
                                   int bits_per_pixel, int pass,
                                   int color_type, const uint8_t *src)
{
    int x, mask, dsp_mask, j, src_x, b, bpp;
    uint8_t *d;
    const uint8_t *s;

98
    mask     = png_pass_mask[pass];
99
    dsp_mask = png_pass_dsp_mask[pass];
100 101

    switch (bits_per_pixel) {
102 103
    case 1:
        src_x = 0;
104
        for (x = 0; x < width; x++) {
105 106 107
            j = (x & 7);
            if ((dsp_mask << j) & 0x80) {
                b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
108
                dst[x >> 3] &= 0xFF7F>>j;
109 110 111 112 113 114
                dst[x >> 3] |= b << (7 - j);
            }
            if ((mask << j) & 0x80)
                src_x++;
        }
        break;
115 116
    case 2:
        src_x = 0;
117 118
        for (x = 0; x < width; x++) {
            int j2 = 2 * (x & 3);
119 120 121 122 123 124 125 126 127 128
            j = (x & 7);
            if ((dsp_mask << j) & 0x80) {
                b = (src[src_x >> 2] >> (6 - 2*(src_x & 3))) & 3;
                dst[x >> 2] &= 0xFF3F>>j2;
                dst[x >> 2] |= b << (6 - j2);
            }
            if ((mask << j) & 0x80)
                src_x++;
        }
        break;
129 130
    case 4:
        src_x = 0;
131
        for (x = 0; x < width; x++) {
132 133 134 135 136 137 138 139 140 141 142
            int j2 = 4*(x&1);
            j = (x & 7);
            if ((dsp_mask << j) & 0x80) {
                b = (src[src_x >> 1] >> (4 - 4*(src_x & 1))) & 15;
                dst[x >> 1] &= 0xFF0F>>j2;
                dst[x >> 1] |= b << (4 - j2);
            }
            if ((mask << j) & 0x80)
                src_x++;
        }
        break;
143 144
    default:
        bpp = bits_per_pixel >> 3;
145 146 147
        d   = dst;
        s   = src;
            for (x = 0; x < width; x++) {
148 149 150 151 152 153 154 155 156 157 158 159
                j = x & 7;
                if ((dsp_mask << j) & 0x80) {
                    memcpy(d, s, bpp);
                }
                d += bpp;
                if ((mask << j) & 0x80)
                    s += bpp;
            }
        break;
    }
}

160 161 162
void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp)
{
    int i;
163
    for (i = 0; i < w; i++) {
164 165 166 167 168 169
        int a, b, c, p, pa, pb, pc;

        a = dst[i - bpp];
        b = top[i];
        c = top[i - bpp];

170
        p  = b - c;
171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191
        pc = a - c;

        pa = abs(p);
        pb = abs(pc);
        pc = abs(p + pc);

        if (pa <= pb && pa <= pc)
            p = a;
        else if (pb <= pc)
            p = b;
        else
            p = c;
        dst[i] = p + src[i];
    }
}

#define UNROLL1(bpp, op) {\
                 r = dst[0];\
    if(bpp >= 2) g = dst[1];\
    if(bpp >= 3) b = dst[2];\
    if(bpp >= 4) a = dst[3];\
192
    for(; i <= size - bpp; i+=bpp) {\
193 194 195 196 197 198 199 200 201 202 203 204 205 206 207
        dst[i+0] = r = op(r, src[i+0], last[i+0]);\
        if(bpp == 1) continue;\
        dst[i+1] = g = op(g, src[i+1], last[i+1]);\
        if(bpp == 2) continue;\
        dst[i+2] = b = op(b, src[i+2], last[i+2]);\
        if(bpp == 3) continue;\
        dst[i+3] = a = op(a, src[i+3], last[i+3]);\
    }\
}

#define UNROLL_FILTER(op)\
         if(bpp == 1) UNROLL1(1, op)\
    else if(bpp == 2) UNROLL1(2, op)\
    else if(bpp == 3) UNROLL1(3, op)\
    else if(bpp == 4) UNROLL1(4, op)\
208 209 210
    for (; i < size; i++) {\
        dst[i] = op(dst[i-bpp], src[i], last[i]);\
    }\
211

212
/* NOTE: 'dst' can be equal to 'last' */
213
static void png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
214 215
                           uint8_t *src, uint8_t *last, int size, int bpp)
{
216
    int i, p, r, g, b, a;
217

218
    switch (filter_type) {
219 220 221 222
    case PNG_FILTER_VALUE_NONE:
        memcpy(dst, src, size);
        break;
    case PNG_FILTER_VALUE_SUB:
223
        for (i = 0; i < bpp; i++) {
224 225
            dst[i] = src[i];
        }
226
        if (bpp == 4) {
227
            p = *(int*)dst;
228
            for (; i < size; i += bpp) {
229
                unsigned s = *(int*)(src + i);
230 231
                p = ((s & 0x7f7f7f7f) + (p & 0x7f7f7f7f)) ^ ((s ^ p) & 0x80808080);
                *(int*)(dst + i) = p;
232 233 234 235
            }
        } else {
#define OP_SUB(x,s,l) x+s
            UNROLL_FILTER(OP_SUB);
236 237 238
        }
        break;
    case PNG_FILTER_VALUE_UP:
239
        dsp->add_bytes_l2(dst, src, last, size);
240 241
        break;
    case PNG_FILTER_VALUE_AVG:
242
        for (i = 0; i < bpp; i++) {
243 244 245
            p = (last[i] >> 1);
            dst[i] = p + src[i];
        }
246 247
#define OP_AVG(x,s,l) (((x + l) >> 1) + s) & 0xff
        UNROLL_FILTER(OP_AVG);
248 249
        break;
    case PNG_FILTER_VALUE_PAETH:
250
        for (i = 0; i < bpp; i++) {
251 252 253
            p = last[i];
            dst[i] = p + src[i];
        }
254
        if (bpp > 2 && size > 4) {
255
            // would write off the end of the array if we let it process the last pixel with bpp=3
256 257
            int w = bpp == 4 ? size : size - 3;
            dsp->add_paeth_prediction(dst + i, src + i, last + i, w - i, bpp);
258
            i = w;
259
        }
260
        ff_add_png_paeth_prediction(dst + i, src + i, last + i, size - i, bpp);
261 262 263 264
        break;
    }
}

265 266 267 268 269 270 271 272 273 274 275
/* This used to be called "deloco" in FFmpeg
 * and is actually an inverse reversible colorspace transformation */
#define YUV2RGB(NAME, TYPE) \
static void deloco_ ## NAME(TYPE *dst, int size, int alpha) \
{ \
    int i; \
    for (i = 0; i < size; i += 3 + alpha) { \
        int g = dst [i+1]; \
        dst[i+0] += g; \
        dst[i+2] += g; \
    } \
276 277
}

278 279
YUV2RGB(rgb8, uint8_t)
YUV2RGB(rgb16, uint16_t)
280

281
/* process exactly one decompressed row */
282
static void png_handle_row(PNGDecContext *s)
283 284 285 286 287 288 289 290 291 292 293
{
    uint8_t *ptr, *last_row;
    int got_line;

    if (!s->interlace_type) {
        ptr = s->image_buf + s->image_linesize * s->y;
            if (s->y == 0)
                last_row = s->last_row;
            else
                last_row = ptr - s->image_linesize;

294
            png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
295
                           last_row, s->row_size, s->bpp);
296
        /* loco lags by 1 row so that it doesn't interfere with top prediction */
297 298 299 300 301 302 303 304 305
        if (s->filter_type == PNG_FILTER_TYPE_LOCO && s->y > 0) {
            if (s->bit_depth == 16) {
                deloco_rgb16((uint16_t *)(ptr - s->image_linesize), s->row_size / 2,
                             s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
            } else {
                deloco_rgb8(ptr - s->image_linesize, s->row_size,
                            s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
            }
        }
306 307 308
        s->y++;
        if (s->y == s->height) {
            s->state |= PNG_ALLIMAGE;
309 310 311 312 313 314 315 316 317
            if (s->filter_type == PNG_FILTER_TYPE_LOCO) {
                if (s->bit_depth == 16) {
                    deloco_rgb16((uint16_t *)ptr, s->row_size / 2,
                                 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
                } else {
                    deloco_rgb8(ptr, s->row_size,
                                s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
                }
            }
318 319 320
        }
    } else {
        got_line = 0;
321
        for (;;) {
322 323 324 325 326 327
            ptr = s->image_buf + s->image_linesize * s->y;
            if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
                /* if we already read one row, it is time to stop to
                   wait for the next one */
                if (got_line)
                    break;
328
                png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
329
                               s->last_row, s->pass_row_size, s->bpp);
Loren Merritt's avatar
Loren Merritt committed
330
                FFSWAP(uint8_t*, s->last_row, s->tmp_row);
331
                FFSWAP(unsigned int, s->last_row_size, s->tmp_row_size);
332 333 334 335 336 337 338 339
                got_line = 1;
            }
            if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
                png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass,
                                       s->color_type, s->last_row);
            }
            s->y++;
            if (s->y == s->height) {
340
                memset(s->last_row, 0, s->row_size);
341
                for (;;) {
342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362
                    if (s->pass == NB_PASSES - 1) {
                        s->state |= PNG_ALLIMAGE;
                        goto the_end;
                    } else {
                        s->pass++;
                        s->y = 0;
                        s->pass_row_size = ff_png_pass_row_size(s->pass,
                                                             s->bits_per_pixel,
                                                             s->width);
                        s->crow_size = s->pass_row_size + 1;
                        if (s->pass_row_size != 0)
                            break;
                        /* skip pass if empty row */
                    }
                }
            }
        }
    the_end: ;
    }
}

363
static int png_decode_idat(PNGDecContext *s, int length)
364 365
{
    int ret;
366
    s->zstream.avail_in = FFMIN(length, bytestream2_get_bytes_left(&s->gb));
367
    s->zstream.next_in  = (unsigned char *)s->gb.buffer;
368
    bytestream2_skip(&s->gb, length);
369 370 371 372 373

    /* decode one line if possible */
    while (s->zstream.avail_in > 0) {
        ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
        if (ret != Z_OK && ret != Z_STREAM_END) {
374 375
            av_log(s->avctx, AV_LOG_ERROR, "inflate returned error %d\n", ret);
            return AVERROR_EXTERNAL;
376 377 378 379 380 381
        }
        if (s->zstream.avail_out == 0) {
            if (!(s->state & PNG_ALLIMAGE)) {
                png_handle_row(s);
            }
            s->zstream.avail_out = s->crow_size;
382
            s->zstream.next_out  = s->crow_buf;
383
        }
384 385 386 387
        if (ret == Z_STREAM_END && s->zstream.avail_in > 0) {
            av_log(NULL, AV_LOG_WARNING, "%d undecompressed bytes left in buffer\n", s->zstream.avail_in);
            return 0;
        }
388 389 390 391
    }
    return 0;
}

392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507
static int decode_zbuf(AVBPrint *bp, const uint8_t *data,
                       const uint8_t *data_end)
{
    z_stream zstream;
    unsigned char *buf;
    unsigned buf_size;
    int ret;

    zstream.zalloc = ff_png_zalloc;
    zstream.zfree  = ff_png_zfree;
    zstream.opaque = NULL;
    if (inflateInit(&zstream) != Z_OK)
        return AVERROR_EXTERNAL;
    zstream.next_in  = (unsigned char *)data;
    zstream.avail_in = data_end - data;
    av_bprint_init(bp, 0, -1);

    while (zstream.avail_in > 0) {
        av_bprint_get_buffer(bp, 1, &buf, &buf_size);
        if (!buf_size) {
            ret = AVERROR(ENOMEM);
            goto fail;
        }
        zstream.next_out  = buf;
        zstream.avail_out = buf_size;
        ret = inflate(&zstream, Z_PARTIAL_FLUSH);
        if (ret != Z_OK && ret != Z_STREAM_END) {
            ret = AVERROR_EXTERNAL;
            goto fail;
        }
        bp->len += zstream.next_out - buf;
        if (ret == Z_STREAM_END)
            break;
    }
    inflateEnd(&zstream);
    bp->str[bp->len] = 0;
    return 0;

fail:
    inflateEnd(&zstream);
    av_bprint_finalize(bp, NULL);
    return ret;
}

static uint8_t *iso88591_to_utf8(const uint8_t *in, size_t size_in)
{
    size_t extra = 0, i;
    uint8_t *out, *q;

    for (i = 0; i < size_in; i++)
        extra += in[i] >= 0x80;
    if (size_in == SIZE_MAX || extra > SIZE_MAX - size_in - 1)
        return NULL;
    q = out = av_malloc(size_in + extra + 1);
    if (!out)
        return NULL;
    for (i = 0; i < size_in; i++) {
        if (in[i] >= 0x80) {
            *(q++) = 0xC0 | (in[i] >> 6);
            *(q++) = 0x80 | (in[i] & 0x3F);
        } else {
            *(q++) = in[i];
        }
    }
    *(q++) = 0;
    return out;
}

static int decode_text_chunk(PNGDecContext *s, uint32_t length, int compressed,
                             AVDictionary **dict)
{
    int ret, method;
    const uint8_t *data        = s->gb.buffer;
    const uint8_t *data_end    = data + length;
    const uint8_t *keyword     = data;
    const uint8_t *keyword_end = memchr(keyword, 0, data_end - keyword);
    uint8_t *kw_utf8 = NULL, *text, *txt_utf8 = NULL;
    unsigned text_len;
    AVBPrint bp;

    if (!keyword_end)
        return AVERROR_INVALIDDATA;
    data = keyword_end + 1;

    if (compressed) {
        if (data == data_end)
            return AVERROR_INVALIDDATA;
        method = *(data++);
        if (method)
            return AVERROR_INVALIDDATA;
        if ((ret = decode_zbuf(&bp, data, data_end)) < 0)
            return ret;
        text_len = bp.len;
        av_bprint_finalize(&bp, (char **)&text);
        if (!text)
            return AVERROR(ENOMEM);
    } else {
        text = (uint8_t *)data;
        text_len = data_end - text;
    }

    kw_utf8  = iso88591_to_utf8(keyword, keyword_end - keyword);
    txt_utf8 = iso88591_to_utf8(text, text_len);
    if (text != data)
        av_free(text);
    if (!(kw_utf8 && txt_utf8)) {
        av_free(kw_utf8);
        av_free(txt_utf8);
        return AVERROR(ENOMEM);
    }

    av_dict_set(dict, kw_utf8, txt_utf8,
                AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
    return 0;
}

508
static int decode_frame(AVCodecContext *avctx,
509
                        void *data, int *got_frame,
510
                        AVPacket *avpkt)
511
{
512
    PNGDecContext * const s = avctx->priv_data;
513 514
    const uint8_t *buf      = avpkt->data;
    int buf_size            = avpkt->size;
515
    AVFrame *p;
516
    AVDictionary *metadata  = NULL;
517
    uint32_t tag, length;
518
    int64_t sig;
Mans Rullgard's avatar
Mans Rullgard committed
519
    int ret;
520

521 522 523 524
    ff_thread_release_buffer(avctx, &s->last_picture);
    FFSWAP(ThreadFrame, s->picture, s->last_picture);
    p = s->picture.f;

525 526
    bytestream2_init(&s->gb, buf, buf_size);

527
    /* check signature */
528 529 530
    sig = bytestream2_get_be64(&s->gb);
    if (sig != PNGSIG &&
        sig != MNGSIG) {
531
        av_log(avctx, AV_LOG_ERROR, "Missing png signature\n");
532
        return AVERROR_INVALIDDATA;
533
    }
534

535 536
    s->y = s->state = 0;

537 538
    /* init the zlib */
    s->zstream.zalloc = ff_png_zalloc;
539
    s->zstream.zfree  = ff_png_zfree;
540 541
    s->zstream.opaque = NULL;
    ret = inflateInit(&s->zstream);
542
    if (ret != Z_OK) {
543 544
        av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret);
        return AVERROR_EXTERNAL;
545
    }
546
    for (;;) {
547 548
        if (bytestream2_get_bytes_left(&s->gb) <= 0) {
            av_log(avctx, AV_LOG_ERROR, "No bytes left\n");
549
            goto fail;
550
        }
551

552
        length = bytestream2_get_be32(&s->gb);
553 554
        if (length > 0x7fffffff || length > bytestream2_get_bytes_left(&s->gb))  {
            av_log(avctx, AV_LOG_ERROR, "chunk too big\n");
555
            goto fail;
556
        }
557
        tag = bytestream2_get_le32(&s->gb);
558 559
        if (avctx->debug & FF_DEBUG_STARTCODE)
            av_log(avctx, AV_LOG_DEBUG, "png: tag=%c%c%c%c length=%u\n",
560 561 562 563
                (tag & 0xff),
                ((tag >> 8) & 0xff),
                ((tag >> 16) & 0xff),
                ((tag >> 24) & 0xff), length);
564
        switch (tag) {
565 566 567
        case MKTAG('I', 'H', 'D', 'R'):
            if (length != 13)
                goto fail;
568 569
            s->width  = bytestream2_get_be32(&s->gb);
            s->height = bytestream2_get_be32(&s->gb);
570 571
            if (av_image_check_size(s->width, s->height, 0, avctx)) {
                s->width = s->height = 0;
572
                av_log(avctx, AV_LOG_ERROR, "Invalid image size\n");
573 574
                goto fail;
            }
575 576 577 578 579 580
            s->bit_depth        = bytestream2_get_byte(&s->gb);
            s->color_type       = bytestream2_get_byte(&s->gb);
            s->compression_type = bytestream2_get_byte(&s->gb);
            s->filter_type      = bytestream2_get_byte(&s->gb);
            s->interlace_type   = bytestream2_get_byte(&s->gb);
            bytestream2_skip(&s->gb, 4); /* crc */
581
            s->state |= PNG_IHDR;
582
            if (avctx->debug & FF_DEBUG_PICT_INFO)
583
                av_log(avctx, AV_LOG_DEBUG, "width=%d height=%d depth=%d color_type=%d "
584
                    "compression_type=%d filter_type=%d interlace_type=%d\n",
585 586
                    s->width, s->height, s->bit_depth, s->color_type,
                    s->compression_type, s->filter_type, s->interlace_type);
587
            break;
588 589 590 591 592 593 594 595 596 597 598 599
        case MKTAG('p', 'H', 'Y', 's'):
            if (s->state & PNG_IDAT) {
                av_log(avctx, AV_LOG_ERROR, "pHYs after IDAT\n");
                goto fail;
            }
            avctx->sample_aspect_ratio.num = bytestream2_get_be32(&s->gb);
            avctx->sample_aspect_ratio.den = bytestream2_get_be32(&s->gb);
            if (avctx->sample_aspect_ratio.num < 0 || avctx->sample_aspect_ratio.den < 0)
                avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
            bytestream2_skip(&s->gb, 1); /* unit specifier */
            bytestream2_skip(&s->gb, 4); /* crc */
            break;
600
        case MKTAG('I', 'D', 'A', 'T'):
601 602
            if (!(s->state & PNG_IHDR)) {
                av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n");
603
                goto fail;
604
            }
605 606
            if (!(s->state & PNG_IDAT)) {
                /* init image info */
607
                avctx->width  = s->width;
608 609
                avctx->height = s->height;

610
                s->channels       = ff_png_get_nb_channels(s->color_type);
611
                s->bits_per_pixel = s->bit_depth * s->channels;
612 613
                s->bpp            = (s->bits_per_pixel + 7) >> 3;
                s->row_size       = (avctx->width * s->bits_per_pixel + 7) >> 3;
614

615
                if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
616
                    s->color_type == PNG_COLOR_TYPE_RGB) {
617
                    avctx->pix_fmt = AV_PIX_FMT_RGB24;
618
                } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
619
                           s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
620
                    avctx->pix_fmt = AV_PIX_FMT_RGBA;
621
                } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
622
                           s->color_type == PNG_COLOR_TYPE_GRAY) {
623
                    avctx->pix_fmt = AV_PIX_FMT_GRAY8;
624 625
                } else if (s->bit_depth == 16 &&
                           s->color_type == PNG_COLOR_TYPE_GRAY) {
626
                    avctx->pix_fmt = AV_PIX_FMT_GRAY16BE;
627 628
                } else if (s->bit_depth == 16 &&
                           s->color_type == PNG_COLOR_TYPE_RGB) {
629
                    avctx->pix_fmt = AV_PIX_FMT_RGB48BE;
630 631
                } else if (s->bit_depth == 16 &&
                           s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
632
                    avctx->pix_fmt = AV_PIX_FMT_RGBA64BE;
633 634
                } else if ((s->bits_per_pixel == 1 || s->bits_per_pixel == 2 || s->bits_per_pixel == 4 || s->bits_per_pixel == 8) &&
                           s->color_type == PNG_COLOR_TYPE_PALETTE) {
635
                    avctx->pix_fmt = AV_PIX_FMT_PAL8;
636
                } else if (s->bit_depth == 1) {
637
                    avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
638 639
                } else if (s->bit_depth == 8 &&
                           s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
640
                    avctx->pix_fmt = AV_PIX_FMT_Y400A;
641
                } else {
642 643 644
                    av_log(avctx, AV_LOG_ERROR, "unsupported bit depth %d "
                                                "and color type %d\n",
                                                 s->bit_depth, s->color_type);
645 646 647
                    goto fail;
                }

648
                if (ff_thread_get_buffer(avctx, &s->picture, AV_GET_BUFFER_FLAG_REF) < 0)
649
                    goto fail;
650 651
                ff_thread_finish_setup(avctx);

652 653
                p->pict_type        = AV_PICTURE_TYPE_I;
                p->key_frame        = 1;
654 655 656 657 658 659 660 661 662 663 664 665
                p->interlaced_frame = !!s->interlace_type;

                /* compute the compressed row size */
                if (!s->interlace_type) {
                    s->crow_size = s->row_size + 1;
                } else {
                    s->pass = 0;
                    s->pass_row_size = ff_png_pass_row_size(s->pass,
                                                         s->bits_per_pixel,
                                                         s->width);
                    s->crow_size = s->pass_row_size + 1;
                }
666
                av_dlog(avctx, "row_size=%d crow_size =%d\n",
667
                        s->row_size, s->crow_size);
668
                s->image_buf      = p->data[0];
669 670
                s->image_linesize = p->linesize[0];
                /* copy the palette if needed */
671
                if (avctx->pix_fmt == AV_PIX_FMT_PAL8)
672 673
                    memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
                /* empty row is used if differencing to the first row */
674
                av_fast_padded_mallocz(&s->last_row, &s->last_row_size, s->row_size);
675 676 677 678
                if (!s->last_row)
                    goto fail;
                if (s->interlace_type ||
                    s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
679
                    av_fast_padded_malloc(&s->tmp_row, &s->tmp_row_size, s->row_size);
680 681 682 683
                    if (!s->tmp_row)
                        goto fail;
                }
                /* compressed row */
684 685
                av_fast_padded_malloc(&s->buffer, &s->buffer_size, s->row_size + 16);
                if (!s->buffer)
686
                    goto fail;
687 688

                /* we want crow_buf+1 to be 16-byte aligned */
689
                s->crow_buf          = s->buffer + 15;
690
                s->zstream.avail_out = s->crow_size;
691
                s->zstream.next_out  = s->crow_buf;
692 693 694 695
            }
            s->state |= PNG_IDAT;
            if (png_decode_idat(s, length) < 0)
                goto fail;
696
            bytestream2_skip(&s->gb, 4); /* crc */
697 698 699 700 701 702 703 704 705
            break;
        case MKTAG('P', 'L', 'T', 'E'):
            {
                int n, i, r, g, b;

                if ((length % 3) != 0 || length > 256 * 3)
                    goto skip_tag;
                /* read the palette */
                n = length / 3;
706
                for (i = 0; i < n; i++) {
707 708 709
                    r = bytestream2_get_byte(&s->gb);
                    g = bytestream2_get_byte(&s->gb);
                    b = bytestream2_get_byte(&s->gb);
710
                    s->palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b;
711
                }
712
                for (; i < 256; i++) {
713
                    s->palette[i] = (0xFFU << 24);
714 715
                }
                s->state |= PNG_PLTE;
716
                bytestream2_skip(&s->gb, 4); /* crc */
717 718 719 720 721 722 723 724 725 726 727
            }
            break;
        case MKTAG('t', 'R', 'N', 'S'):
            {
                int v, i;

                /* read the transparency. XXX: Only palette mode supported */
                if (s->color_type != PNG_COLOR_TYPE_PALETTE ||
                    length > 256 ||
                    !(s->state & PNG_PLTE))
                    goto skip_tag;
728
                for (i = 0; i < length; i++) {
729
                    v = bytestream2_get_byte(&s->gb);
730 731
                    s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
                }
732
                bytestream2_skip(&s->gb, 4); /* crc */
733 734
            }
            break;
735 736 737 738 739 740 741 742 743 744
        case MKTAG('t', 'E', 'X', 't'):
            if (decode_text_chunk(s, length, 0, &metadata) < 0)
                av_log(avctx, AV_LOG_WARNING, "Broken tEXt chunk\n");
            bytestream2_skip(&s->gb, length + 4);
            break;
        case MKTAG('z', 'T', 'X', 't'):
            if (decode_text_chunk(s, length, 1, &metadata) < 0)
                av_log(avctx, AV_LOG_WARNING, "Broken zTXt chunk\n");
            bytestream2_skip(&s->gb, length + 4);
            break;
745
        case MKTAG('I', 'E', 'N', 'D'):
746
            if (!(s->state & PNG_ALLIMAGE))
747
                av_log(avctx, AV_LOG_ERROR, "IEND without all image\n");
748
            if (!(s->state & (PNG_ALLIMAGE|PNG_IDAT))) {
749
                goto fail;
750
            }
751
            bytestream2_skip(&s->gb, 4); /* crc */
752 753 754 755
            goto exit_loop;
        default:
            /* skip tag */
        skip_tag:
756
            bytestream2_skip(&s->gb, length + 4);
757 758 759 760
            break;
        }
    }
 exit_loop:
761

762
    if (s->bits_per_pixel == 1 && s->color_type == PNG_COLOR_TYPE_PALETTE){
763
        int i, j, k;
764
        uint8_t *pd = p->data[0];
765
        for (j = 0; j < s->height; j++) {
766 767 768 769 770
            i = s->width / 8;
            for (k = 7; k >= 1; k--)
                if ((s->width&7) >= k)
                    pd[8*i + k - 1] = (pd[i]>>8-k) & 1;
            for (i--; i >= 0; i--) {
771 772 773 774 775 776 777 778
                pd[8*i + 7]=  pd[i]     & 1;
                pd[8*i + 6]= (pd[i]>>1) & 1;
                pd[8*i + 5]= (pd[i]>>2) & 1;
                pd[8*i + 4]= (pd[i]>>3) & 1;
                pd[8*i + 3]= (pd[i]>>4) & 1;
                pd[8*i + 2]= (pd[i]>>5) & 1;
                pd[8*i + 1]= (pd[i]>>6) & 1;
                pd[8*i + 0]=  pd[i]>>7;
779 780 781 782
            }
            pd += s->image_linesize;
        }
    }
783
    if (s->bits_per_pixel == 2){
784
        int i, j;
785
        uint8_t *pd = p->data[0];
786 787
        for (j = 0; j < s->height; j++) {
            i = s->width / 4;
788
            if (s->color_type == PNG_COLOR_TYPE_PALETTE){
789 790 791 792 793 794 795 796 797
                if ((s->width&3) >= 3) pd[4*i + 2]= (pd[i] >> 2) & 3;
                if ((s->width&3) >= 2) pd[4*i + 1]= (pd[i] >> 4) & 3;
                if ((s->width&3) >= 1) pd[4*i + 0]=  pd[i] >> 6;
                for (i--; i >= 0; i--) {
                    pd[4*i + 3]=  pd[i]     & 3;
                    pd[4*i + 2]= (pd[i]>>2) & 3;
                    pd[4*i + 1]= (pd[i]>>4) & 3;
                    pd[4*i + 0]=  pd[i]>>6;
                }
798
            } else {
799 800 801 802 803 804 805 806
                if ((s->width&3) >= 3) pd[4*i + 2]= ((pd[i]>>2) & 3)*0x55;
                if ((s->width&3) >= 2) pd[4*i + 1]= ((pd[i]>>4) & 3)*0x55;
                if ((s->width&3) >= 1) pd[4*i + 0]= ( pd[i]>>6     )*0x55;
                for (i--; i >= 0; i--) {
                    pd[4*i + 3]= ( pd[i]     & 3)*0x55;
                    pd[4*i + 2]= ((pd[i]>>2) & 3)*0x55;
                    pd[4*i + 1]= ((pd[i]>>4) & 3)*0x55;
                    pd[4*i + 0]= ( pd[i]>>6     )*0x55;
807 808
                }
            }
809 810 811
            pd += s->image_linesize;
        }
    }
812
    if (s->bits_per_pixel == 4){
813
        int i, j;
814
        uint8_t *pd = p->data[0];
815 816
        for (j = 0; j < s->height; j++) {
            i = s->width/2;
817
            if (s->color_type == PNG_COLOR_TYPE_PALETTE){
818
                if (s->width&1) pd[2*i+0]= pd[i]>>4;
819 820 821
                for (i--; i >= 0; i--) {
                pd[2*i + 1] = pd[i] & 15;
                pd[2*i + 0] = pd[i] >> 4;
822
            }
823
            } else {
824 825 826 827
                if (s->width & 1) pd[2*i + 0]= (pd[i] >> 4) * 0x11;
                for (i--; i >= 0; i--) {
                    pd[2*i + 1] = (pd[i] & 15) * 0x11;
                    pd[2*i + 0] = (pd[i] >> 4) * 0x11;
828 829
                }
            }
830 831 832 833
            pd += s->image_linesize;
        }
    }

834
     /* handle p-frames only if a predecessor frame is available */
835
     if (s->last_picture.f->data[0]) {
836
         if (   !(avpkt->flags & AV_PKT_FLAG_KEY) && avctx->codec_tag != AV_RL32("MPNG")
837 838 839
            && s->last_picture.f->width == p->width
            && s->last_picture.f->height== p->height
            && s->last_picture.f->format== p->format
840
         ) {
841
            int i, j;
842
            uint8_t *pd      = p->data[0];
843
            uint8_t *pd_last = s->last_picture.f->data[0];
844

845
            ff_thread_await_progress(&s->last_picture, INT_MAX, 0);
846 847
            for (j = 0; j < s->height; j++) {
                for (i = 0; i < s->width * s->bpp; i++) {
848 849
                    pd[i] += pd_last[i];
                }
850
                pd      += s->image_linesize;
851 852 853 854
                pd_last += s->image_linesize;
            }
        }
    }
855
    ff_thread_report_progress(&s->picture, INT_MAX, 0);
856

857
    av_frame_set_metadata(p, metadata);
858
    metadata   = NULL;
859

860 861
    if ((ret = av_frame_ref(data, s->picture.f)) < 0)
        return ret;
862

863
    *got_frame = 1;
864

865
    ret = bytestream2_tell(&s->gb);
866 867
 the_end:
    inflateEnd(&s->zstream);
868
    s->crow_buf = NULL;
869 870
    return ret;
 fail:
871
    av_dict_free(&metadata);
872
    ff_thread_report_progress(&s->picture, INT_MAX, 0);
873
    ret = AVERROR_INVALIDDATA;
874 875 876
    goto the_end;
}

877 878 879 880 881 882 883 884 885 886 887 888 889 890 891
static int update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
{
    PNGDecContext *psrc = src->priv_data;
    PNGDecContext *pdst = dst->priv_data;

    if (dst == src)
        return 0;

    ff_thread_release_buffer(dst, &pdst->picture);
    if (psrc->picture.f->data[0])
        return ff_thread_ref_frame(&pdst->picture, &psrc->picture);

    return 0;
}

892 893
static av_cold int png_dec_init(AVCodecContext *avctx)
{
894 895
    PNGDecContext *s = avctx->priv_data;

896 897 898 899
    s->avctx = avctx;
    s->last_picture.f = av_frame_alloc();
    s->picture.f = av_frame_alloc();
    if (!s->last_picture.f || !s->picture.f)
900
        return AVERROR(ENOMEM);
901

902 903 904 905
    if (!avctx->internal->is_copy) {
        avctx->internal->allocate_progress = 1;
        ff_pngdsp_init(&s->dsp);
    }
906

907 908 909
    return 0;
}

910 911 912 913
static av_cold int png_dec_end(AVCodecContext *avctx)
{
    PNGDecContext *s = avctx->priv_data;

914 915 916 917
    ff_thread_release_buffer(avctx, &s->last_picture);
    av_frame_free(&s->last_picture.f);
    ff_thread_release_buffer(avctx, &s->picture);
    av_frame_free(&s->picture.f);
918 919 920 921
    av_freep(&s->buffer);
    s->buffer_size = 0;
    av_freep(&s->last_row);
    s->last_row_size = 0;
922 923
    av_freep(&s->tmp_row);
    s->tmp_row_size = 0;
924 925 926 927

    return 0;
}

928
AVCodec ff_png_decoder = {
929
    .name           = "png",
930
    .long_name      = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),
931
    .type           = AVMEDIA_TYPE_VIDEO,
932
    .id             = AV_CODEC_ID_PNG,
933 934 935 936
    .priv_data_size = sizeof(PNGDecContext),
    .init           = png_dec_init,
    .close          = png_dec_end,
    .decode         = decode_frame,
937 938 939
    .init_thread_copy = ONLY_IF_THREADS_ENABLED(png_dec_init),
    .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
940
};