/* * PNG image format * Copyright (c) 2003 Fabrice Bellard * * 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 */ //#define DEBUG #include "libavutil/avassert.h" #include "libavutil/bprint.h" #include "libavutil/imgutils.h" #include "avcodec.h" #include "bytestream.h" #include "internal.h" #include "apng.h" #include "png.h" #include "pngdsp.h" #include "thread.h" #include typedef struct PNGDecContext { PNGDSPContext dsp; AVCodecContext *avctx; GetByteContext gb; ThreadFrame previous_picture; ThreadFrame last_picture; ThreadFrame picture; int state; int width, height; int cur_w, cur_h; int last_w, last_h; int x_offset, y_offset; int last_x_offset, last_y_offset; uint8_t dispose_op, blend_op; uint8_t last_dispose_op; int bit_depth; int color_type; int compression_type; int interlace_type; int filter_type; int channels; int bits_per_pixel; int bpp; int has_trns; uint8_t transparent_color_be[6]; uint8_t *image_buf; int image_linesize; uint32_t palette[256]; uint8_t *crow_buf; uint8_t *last_row; unsigned int last_row_size; uint8_t *tmp_row; unsigned int tmp_row_size; uint8_t *buffer; int buffer_size; 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; /* 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, }; /* Mask to determine which y pixels can be written in a pass */ static const uint8_t png_pass_dsp_ymask[NB_PASSES] = { 0xff, 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, }; /* 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 * is the original image width. We also do pixel format conversion at * 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; mask = png_pass_mask[pass]; dsp_mask = png_pass_dsp_mask[pass]; switch (bits_per_pixel) { case 1: src_x = 0; for (x = 0; x < width; x++) { j = (x & 7); if ((dsp_mask << j) & 0x80) { b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1; dst[x >> 3] &= 0xFF7F>>j; dst[x >> 3] |= b << (7 - j); } if ((mask << j) & 0x80) src_x++; } break; case 2: src_x = 0; for (x = 0; x < width; x++) { int j2 = 2 * (x & 3); 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; case 4: src_x = 0; for (x = 0; x < width; x++) { 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; default: bpp = bits_per_pixel >> 3; d = dst; s = src; for (x = 0; x < width; x++) { j = x & 7; if ((dsp_mask << j) & 0x80) { memcpy(d, s, bpp); } d += bpp; if ((mask << j) & 0x80) s += bpp; } break; } } void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp) { int i; for (i = 0; i < w; i++) { int a, b, c, p, pa, pb, pc; a = dst[i - bpp]; b = top[i]; c = top[i - bpp]; p = b - c; 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]; \ for (; i <= size - bpp; i += bpp) { \ 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) \ } \ for (; i < size; i++) { \ dst[i] = op(dst[i - bpp], src[i], last[i]); \ } /* NOTE: 'dst' can be equal to 'last' */ static void png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type, uint8_t *src, uint8_t *last, int size, int bpp) { int i, p, r, g, b, a; switch (filter_type) { case PNG_FILTER_VALUE_NONE: memcpy(dst, src, size); break; case PNG_FILTER_VALUE_SUB: for (i = 0; i < bpp; i++) dst[i] = src[i]; if (bpp == 4) { p = *(int *)dst; for (; i < size; i += bpp) { unsigned s = *(int *)(src + i); p = ((s & 0x7f7f7f7f) + (p & 0x7f7f7f7f)) ^ ((s ^ p) & 0x80808080); *(int *)(dst + i) = p; } } else { #define OP_SUB(x, s, l) ((x) + (s)) UNROLL_FILTER(OP_SUB); } break; case PNG_FILTER_VALUE_UP: dsp->add_bytes_l2(dst, src, last, size); break; case PNG_FILTER_VALUE_AVG: for (i = 0; i < bpp; i++) { p = (last[i] >> 1); dst[i] = p + src[i]; } #define OP_AVG(x, s, l) (((((x) + (l)) >> 1) + (s)) & 0xff) UNROLL_FILTER(OP_AVG); break; case PNG_FILTER_VALUE_PAETH: for (i = 0; i < bpp; i++) { p = last[i]; dst[i] = p + src[i]; } if (bpp > 2 && size > 4) { /* would write off the end of the array if we let it process * the last pixel with bpp=3 */ int w = (bpp & 3) ? size - 3 : size; if (w > i) { dsp->add_paeth_prediction(dst + i, src + i, last + i, size - i, bpp); i = w; } } ff_add_png_paeth_prediction(dst + i, src + i, last + i, size - i, bpp); break; } } /* 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; \ } \ } YUV2RGB(rgb8, uint8_t) YUV2RGB(rgb16, uint16_t) /* process exactly one decompressed row */ static void png_handle_row(PNGDecContext *s) { uint8_t *ptr, *last_row; int got_line; if (!s->interlace_type) { ptr = s->image_buf + s->image_linesize * (s->y + s->y_offset) + s->x_offset * s->bpp; if (s->y == 0) last_row = s->last_row; else last_row = ptr - s->image_linesize; png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1, last_row, s->row_size, s->bpp); /* loco lags by 1 row so that it doesn't interfere with top prediction */ 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); } } s->y++; if (s->y == s->cur_h) { s->state |= PNG_ALLIMAGE; 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); } } } } else { got_line = 0; for (;;) { ptr = s->image_buf + s->image_linesize * (s->y + s->y_offset) + s->x_offset * s->bpp; 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; png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1, s->last_row, s->pass_row_size, s->bpp); FFSWAP(uint8_t *, s->last_row, s->tmp_row); FFSWAP(unsigned int, s->last_row_size, s->tmp_row_size); got_line = 1; } if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) { png_put_interlaced_row(ptr, s->cur_w, s->bits_per_pixel, s->pass, s->color_type, s->last_row); } s->y++; if (s->y == s->cur_h) { memset(s->last_row, 0, s->row_size); for (;;) { 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->cur_w); s->crow_size = s->pass_row_size + 1; if (s->pass_row_size != 0) break; /* skip pass if empty row */ } } } } the_end:; } } static int png_decode_idat(PNGDecContext *s, int length) { int ret; s->zstream.avail_in = FFMIN(length, bytestream2_get_bytes_left(&s->gb)); s->zstream.next_in = (unsigned char *)s->gb.buffer; bytestream2_skip(&s->gb, length); /* 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) { av_log(s->avctx, AV_LOG_ERROR, "inflate returned error %d\n", ret); return AVERROR_EXTERNAL; } if (s->zstream.avail_out == 0) { if (!(s->state & PNG_ALLIMAGE)) { png_handle_row(s); } s->zstream.avail_out = s->crow_size; s->zstream.next_out = s->crow_buf; } 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; } } return 0; } 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; } static int decode_ihdr_chunk(AVCodecContext *avctx, PNGDecContext *s, uint32_t length) { if (length != 13) return AVERROR_INVALIDDATA; if (s->state & PNG_IDAT) { av_log(avctx, AV_LOG_ERROR, "IHDR after IDAT\n"); return AVERROR_INVALIDDATA; } if (s->state & PNG_IHDR) { av_log(avctx, AV_LOG_ERROR, "Multiple IHDR\n"); return AVERROR_INVALIDDATA; } s->width = s->cur_w = bytestream2_get_be32(&s->gb); s->height = s->cur_h = bytestream2_get_be32(&s->gb); if (av_image_check_size(s->width, s->height, 0, avctx)) { s->cur_w = s->cur_h = s->width = s->height = 0; av_log(avctx, AV_LOG_ERROR, "Invalid image size\n"); return AVERROR_INVALIDDATA; } 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 */ s->state |= PNG_IHDR; if (avctx->debug & FF_DEBUG_PICT_INFO) av_log(avctx, AV_LOG_DEBUG, "width=%d height=%d depth=%d color_type=%d " "compression_type=%d filter_type=%d interlace_type=%d\n", s->width, s->height, s->bit_depth, s->color_type, s->compression_type, s->filter_type, s->interlace_type); return 0; } static int decode_phys_chunk(AVCodecContext *avctx, PNGDecContext *s) { if (s->state & PNG_IDAT) { av_log(avctx, AV_LOG_ERROR, "pHYs after IDAT\n"); return AVERROR_INVALIDDATA; } 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 */ return 0; } static int decode_idat_chunk(AVCodecContext *avctx, PNGDecContext *s, uint32_t length, AVFrame *p) { int ret; size_t byte_depth = s->bit_depth > 8 ? 2 : 1; if (!(s->state & PNG_IHDR)) { av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n"); return AVERROR_INVALIDDATA; } if (!(s->state & PNG_IDAT)) { /* init image info */ avctx->width = s->width; avctx->height = s->height; s->channels = ff_png_get_nb_channels(s->color_type); s->bits_per_pixel = s->bit_depth * s->channels; s->bpp = (s->bits_per_pixel + 7) >> 3; s->row_size = (s->cur_w * s->bits_per_pixel + 7) >> 3; if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) && s->color_type == PNG_COLOR_TYPE_RGB) { avctx->pix_fmt = AV_PIX_FMT_RGB24; } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) && s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { avctx->pix_fmt = AV_PIX_FMT_RGBA; } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) && s->color_type == PNG_COLOR_TYPE_GRAY) { avctx->pix_fmt = AV_PIX_FMT_GRAY8; } else if (s->bit_depth == 16 && s->color_type == PNG_COLOR_TYPE_GRAY) { avctx->pix_fmt = AV_PIX_FMT_GRAY16BE; } else if (s->bit_depth == 16 && s->color_type == PNG_COLOR_TYPE_RGB) { avctx->pix_fmt = AV_PIX_FMT_RGB48BE; } else if (s->bit_depth == 16 && s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { avctx->pix_fmt = AV_PIX_FMT_RGBA64BE; } 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) { avctx->pix_fmt = AV_PIX_FMT_PAL8; } else if (s->bit_depth == 1 && s->bits_per_pixel == 1 && avctx->codec_id != AV_CODEC_ID_APNG) { avctx->pix_fmt = AV_PIX_FMT_MONOBLACK; } else if (s->bit_depth == 8 && s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) { avctx->pix_fmt = AV_PIX_FMT_YA8; } else if (s->bit_depth == 16 && s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) { avctx->pix_fmt = AV_PIX_FMT_YA16BE; } else { av_log(avctx, AV_LOG_ERROR, "unsupported bit depth %d " "and color type %d\n", s->bit_depth, s->color_type); return AVERROR_INVALIDDATA; } if (s->has_trns && s->color_type != PNG_COLOR_TYPE_PALETTE) { switch (avctx->pix_fmt) { case AV_PIX_FMT_RGB24: avctx->pix_fmt = AV_PIX_FMT_RGBA; break; case AV_PIX_FMT_RGB48BE: avctx->pix_fmt = AV_PIX_FMT_RGBA64BE; break; case AV_PIX_FMT_GRAY8: avctx->pix_fmt = AV_PIX_FMT_YA8; break; case AV_PIX_FMT_GRAY16BE: avctx->pix_fmt = AV_PIX_FMT_YA16BE; break; default: av_assert0(0); } s->bpp += byte_depth; } if ((ret = ff_thread_get_buffer(avctx, &s->picture, AV_GET_BUFFER_FLAG_REF)) < 0) return ret; if (avctx->codec_id == AV_CODEC_ID_APNG && s->last_dispose_op != APNG_DISPOSE_OP_PREVIOUS) { ff_thread_release_buffer(avctx, &s->previous_picture); if ((ret = ff_thread_get_buffer(avctx, &s->previous_picture, AV_GET_BUFFER_FLAG_REF)) < 0) return ret; } ff_thread_finish_setup(avctx); p->pict_type = AV_PICTURE_TYPE_I; p->key_frame = 1; 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->cur_w); s->crow_size = s->pass_row_size + 1; } ff_dlog(avctx, "row_size=%d crow_size =%d\n", s->row_size, s->crow_size); s->image_buf = p->data[0]; s->image_linesize = p->linesize[0]; /* copy the palette if needed */ if (avctx->pix_fmt == AV_PIX_FMT_PAL8) memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t)); /* empty row is used if differencing to the first row */ av_fast_padded_mallocz(&s->last_row, &s->last_row_size, s->row_size); if (!s->last_row) return AVERROR_INVALIDDATA; if (s->interlace_type || s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { av_fast_padded_malloc(&s->tmp_row, &s->tmp_row_size, s->row_size); if (!s->tmp_row) return AVERROR_INVALIDDATA; } /* compressed row */ av_fast_padded_malloc(&s->buffer, &s->buffer_size, s->row_size + 16); if (!s->buffer) return AVERROR(ENOMEM); /* we want crow_buf+1 to be 16-byte aligned */ s->crow_buf = s->buffer + 15; s->zstream.avail_out = s->crow_size; s->zstream.next_out = s->crow_buf; } s->state |= PNG_IDAT; /* set image to non-transparent bpp while decompressing */ if (s->has_trns && s->color_type != PNG_COLOR_TYPE_PALETTE) s->bpp -= byte_depth; ret = png_decode_idat(s, length); if (s->has_trns && s->color_type != PNG_COLOR_TYPE_PALETTE) s->bpp += byte_depth; if (ret < 0) return ret; bytestream2_skip(&s->gb, 4); /* crc */ return 0; } static int decode_plte_chunk(AVCodecContext *avctx, PNGDecContext *s, uint32_t length) { int n, i, r, g, b; if ((length % 3) != 0 || length > 256 * 3) return AVERROR_INVALIDDATA; /* read the palette */ n = length / 3; for (i = 0; i < n; i++) { r = bytestream2_get_byte(&s->gb); g = bytestream2_get_byte(&s->gb); b = bytestream2_get_byte(&s->gb); s->palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b; } for (; i < 256; i++) s->palette[i] = (0xFFU << 24); s->state |= PNG_PLTE; bytestream2_skip(&s->gb, 4); /* crc */ return 0; } static int decode_trns_chunk(AVCodecContext *avctx, PNGDecContext *s, uint32_t length) { int v, i; if (s->color_type == PNG_COLOR_TYPE_PALETTE) { if (length > 256 || !(s->state & PNG_PLTE)) return AVERROR_INVALIDDATA; for (i = 0; i < length; i++) { v = bytestream2_get_byte(&s->gb); s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24); } } else if (s->color_type == PNG_COLOR_TYPE_GRAY || s->color_type == PNG_COLOR_TYPE_RGB) { if ((s->color_type == PNG_COLOR_TYPE_GRAY && length != 2) || (s->color_type == PNG_COLOR_TYPE_RGB && length != 6)) return AVERROR_INVALIDDATA; for (i = 0; i < length / 2; i++) { /* only use the least significant bits */ v = bytestream2_get_be16(&s->gb) & ((1 << s->bit_depth) - 1); if (s->bit_depth > 8) AV_WB16(&s->transparent_color_be[2 * i], v); else s->transparent_color_be[i] = v; } } else { return AVERROR_INVALIDDATA; } bytestream2_skip(&s->gb, 4); /* crc */ s->has_trns = 1; return 0; } static void handle_small_bpp(PNGDecContext *s, AVFrame *p) { if (s->bits_per_pixel == 1 && s->color_type == PNG_COLOR_TYPE_PALETTE) { int i, j, k; uint8_t *pd = p->data[0]; for (j = 0; j < s->height; j++) { 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--) { 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; } pd += s->image_linesize; } } else if (s->bits_per_pixel == 2) { int i, j; uint8_t *pd = p->data[0]; for (j = 0; j < s->height; j++) { i = s->width / 4; if (s->color_type == PNG_COLOR_TYPE_PALETTE) { 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; } } else { 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; } } pd += s->image_linesize; } } else if (s->bits_per_pixel == 4) { int i, j; uint8_t *pd = p->data[0]; for (j = 0; j < s->height; j++) { i = s->width/2; if (s->color_type == PNG_COLOR_TYPE_PALETTE) { if (s->width&1) pd[2*i+0]= pd[i]>>4; for (i--; i >= 0; i--) { pd[2*i + 1] = pd[i] & 15; pd[2*i + 0] = pd[i] >> 4; } } else { 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; } } pd += s->image_linesize; } } } static int decode_fctl_chunk(AVCodecContext *avctx, PNGDecContext *s, uint32_t length) { uint32_t sequence_number; int cur_w, cur_h, x_offset, y_offset, dispose_op, blend_op; if (length != 26) return AVERROR_INVALIDDATA; if (!(s->state & PNG_IHDR)) { av_log(avctx, AV_LOG_ERROR, "fctl before IHDR\n"); return AVERROR_INVALIDDATA; } s->last_w = s->cur_w; s->last_h = s->cur_h; s->last_x_offset = s->x_offset; s->last_y_offset = s->y_offset; s->last_dispose_op = s->dispose_op; sequence_number = bytestream2_get_be32(&s->gb); cur_w = bytestream2_get_be32(&s->gb); cur_h = bytestream2_get_be32(&s->gb); x_offset = bytestream2_get_be32(&s->gb); y_offset = bytestream2_get_be32(&s->gb); bytestream2_skip(&s->gb, 4); /* delay_num (2), delay_den (2) */ dispose_op = bytestream2_get_byte(&s->gb); blend_op = bytestream2_get_byte(&s->gb); bytestream2_skip(&s->gb, 4); /* crc */ if (sequence_number == 0 && (cur_w != s->width || cur_h != s->height || x_offset != 0 || y_offset != 0) || cur_w <= 0 || cur_h <= 0 || x_offset < 0 || y_offset < 0 || cur_w > s->width - x_offset|| cur_h > s->height - y_offset) return AVERROR_INVALIDDATA; if (sequence_number == 0 && dispose_op == APNG_DISPOSE_OP_PREVIOUS) { // No previous frame to revert to for the first frame // Spec says to just treat it as a APNG_DISPOSE_OP_BACKGROUND dispose_op = APNG_DISPOSE_OP_BACKGROUND; } if (blend_op == APNG_BLEND_OP_OVER && !s->has_trns && ( avctx->pix_fmt == AV_PIX_FMT_RGB24 || avctx->pix_fmt == AV_PIX_FMT_RGB48BE || avctx->pix_fmt == AV_PIX_FMT_PAL8 || avctx->pix_fmt == AV_PIX_FMT_GRAY8 || avctx->pix_fmt == AV_PIX_FMT_GRAY16BE || avctx->pix_fmt == AV_PIX_FMT_MONOBLACK )) { // APNG_BLEND_OP_OVER is the same as APNG_BLEND_OP_SOURCE when there is no alpha channel blend_op = APNG_BLEND_OP_SOURCE; } s->cur_w = cur_w; s->cur_h = cur_h; s->x_offset = x_offset; s->y_offset = y_offset; s->dispose_op = dispose_op; s->blend_op = blend_op; return 0; } static void handle_p_frame_png(PNGDecContext *s, AVFrame *p) { int i, j; uint8_t *pd = p->data[0]; uint8_t *pd_last = s->last_picture.f->data[0]; int ls = FFMIN(av_image_get_linesize(p->format, s->width, 0), s->width * s->bpp); ff_thread_await_progress(&s->last_picture, INT_MAX, 0); for (j = 0; j < s->height; j++) { for (i = 0; i < ls; i++) pd[i] += pd_last[i]; pd += s->image_linesize; pd_last += s->image_linesize; } } // divide by 255 and round to nearest // apply a fast variant: (X+127)/255 = ((X+127)*257+257)>>16 = ((X+128)*257)>>16 #define FAST_DIV255(x) ((((x) + 128) * 257) >> 16) static int handle_p_frame_apng(AVCodecContext *avctx, PNGDecContext *s, AVFrame *p) { size_t x, y; uint8_t *buffer = av_malloc(s->image_linesize * s->height); if (!buffer) return AVERROR(ENOMEM); if (s->blend_op == APNG_BLEND_OP_OVER && avctx->pix_fmt != AV_PIX_FMT_RGBA && avctx->pix_fmt != AV_PIX_FMT_GRAY8A && avctx->pix_fmt != AV_PIX_FMT_PAL8) { avpriv_request_sample(avctx, "Blending with pixel format %s", av_get_pix_fmt_name(avctx->pix_fmt)); return AVERROR_PATCHWELCOME; } // Do the disposal operation specified by the last frame on the frame if (s->last_dispose_op != APNG_DISPOSE_OP_PREVIOUS) { ff_thread_await_progress(&s->last_picture, INT_MAX, 0); memcpy(buffer, s->last_picture.f->data[0], s->image_linesize * s->height); if (s->last_dispose_op == APNG_DISPOSE_OP_BACKGROUND) for (y = s->last_y_offset; y < s->last_y_offset + s->last_h; ++y) memset(buffer + s->image_linesize * y + s->bpp * s->last_x_offset, 0, s->bpp * s->last_w); memcpy(s->previous_picture.f->data[0], buffer, s->image_linesize * s->height); ff_thread_report_progress(&s->previous_picture, INT_MAX, 0); } else { ff_thread_await_progress(&s->previous_picture, INT_MAX, 0); memcpy(buffer, s->previous_picture.f->data[0], s->image_linesize * s->height); } // Perform blending if (s->blend_op == APNG_BLEND_OP_SOURCE) { for (y = s->y_offset; y < s->y_offset + s->cur_h; ++y) { size_t row_start = s->image_linesize * y + s->bpp * s->x_offset; memcpy(buffer + row_start, p->data[0] + row_start, s->bpp * s->cur_w); } } else { // APNG_BLEND_OP_OVER for (y = s->y_offset; y < s->y_offset + s->cur_h; ++y) { uint8_t *foreground = p->data[0] + s->image_linesize * y + s->bpp * s->x_offset; uint8_t *background = buffer + s->image_linesize * y + s->bpp * s->x_offset; for (x = s->x_offset; x < s->x_offset + s->cur_w; ++x, foreground += s->bpp, background += s->bpp) { size_t b; uint8_t foreground_alpha, background_alpha, output_alpha; uint8_t output[4]; // Since we might be blending alpha onto alpha, we use the following equations: // output_alpha = foreground_alpha + (1 - foreground_alpha) * background_alpha // output = (foreground_alpha * foreground + (1 - foreground_alpha) * background_alpha * background) / output_alpha switch (avctx->pix_fmt) { case AV_PIX_FMT_RGBA: foreground_alpha = foreground[3]; background_alpha = background[3]; break; case AV_PIX_FMT_GRAY8A: foreground_alpha = foreground[1]; background_alpha = background[1]; break; case AV_PIX_FMT_PAL8: foreground_alpha = s->palette[foreground[0]] >> 24; background_alpha = s->palette[background[0]] >> 24; break; } if (foreground_alpha == 0) continue; if (foreground_alpha == 255) { memcpy(background, foreground, s->bpp); continue; } if (avctx->pix_fmt == AV_PIX_FMT_PAL8) { // TODO: Alpha blending with PAL8 will likely need the entire image converted over to RGBA first avpriv_request_sample(avctx, "Alpha blending palette samples"); background[0] = foreground[0]; continue; } output_alpha = foreground_alpha + FAST_DIV255((255 - foreground_alpha) * background_alpha); for (b = 0; b < s->bpp - 1; ++b) { if (output_alpha == 0) { output[b] = 0; } else if (background_alpha == 255) { output[b] = FAST_DIV255(foreground_alpha * foreground[b] + (255 - foreground_alpha) * background[b]); } else { output[b] = (255 * foreground_alpha * foreground[b] + (255 - foreground_alpha) * background_alpha * background[b]) / (255 * output_alpha); } } output[b] = output_alpha; memcpy(background, output, s->bpp); } } } // Copy blended buffer into the frame and free memcpy(p->data[0], buffer, s->image_linesize * s->height); av_free(buffer); return 0; } static int decode_frame_common(AVCodecContext *avctx, PNGDecContext *s, AVFrame *p, AVPacket *avpkt) { AVDictionary *metadata = NULL; uint32_t tag, length; int decode_next_dat = 0; int ret; for (;;) { length = bytestream2_get_bytes_left(&s->gb); if (length <= 0) { if (CONFIG_APNG_DECODER && avctx->codec_id == AV_CODEC_ID_APNG && length == 0) { if (!(s->state & PNG_IDAT)) return 0; else goto exit_loop; } av_log(avctx, AV_LOG_ERROR, "%d bytes left\n", length); if ( s->state & PNG_ALLIMAGE && avctx->strict_std_compliance <= FF_COMPLIANCE_NORMAL) goto exit_loop; ret = AVERROR_INVALIDDATA; goto fail; } length = bytestream2_get_be32(&s->gb); if (length > 0x7fffffff || length > bytestream2_get_bytes_left(&s->gb)) { av_log(avctx, AV_LOG_ERROR, "chunk too big\n"); ret = AVERROR_INVALIDDATA; goto fail; } tag = bytestream2_get_le32(&s->gb); if (avctx->debug & FF_DEBUG_STARTCODE) av_log(avctx, AV_LOG_DEBUG, "png: tag=%c%c%c%c length=%u\n", (tag & 0xff), ((tag >> 8) & 0xff), ((tag >> 16) & 0xff), ((tag >> 24) & 0xff), length); switch (tag) { case MKTAG('I', 'H', 'D', 'R'): if ((ret = decode_ihdr_chunk(avctx, s, length)) < 0) goto fail; break; case MKTAG('p', 'H', 'Y', 's'): if ((ret = decode_phys_chunk(avctx, s)) < 0) goto fail; break; case MKTAG('f', 'c', 'T', 'L'): if (!CONFIG_APNG_DECODER || avctx->codec_id != AV_CODEC_ID_APNG) goto skip_tag; if ((ret = decode_fctl_chunk(avctx, s, length)) < 0) goto fail; decode_next_dat = 1; break; case MKTAG('f', 'd', 'A', 'T'): if (!CONFIG_APNG_DECODER || avctx->codec_id != AV_CODEC_ID_APNG) goto skip_tag; if (!decode_next_dat) { ret = AVERROR_INVALIDDATA; goto fail; } bytestream2_get_be32(&s->gb); length -= 4; /* fallthrough */ case MKTAG('I', 'D', 'A', 'T'): if (CONFIG_APNG_DECODER && avctx->codec_id == AV_CODEC_ID_APNG && !decode_next_dat) goto skip_tag; if ((ret = decode_idat_chunk(avctx, s, length, p)) < 0) goto fail; break; case MKTAG('P', 'L', 'T', 'E'): if (decode_plte_chunk(avctx, s, length) < 0) goto skip_tag; break; case MKTAG('t', 'R', 'N', 'S'): if (decode_trns_chunk(avctx, s, length) < 0) goto skip_tag; break; 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; case MKTAG('I', 'E', 'N', 'D'): if (!(s->state & PNG_ALLIMAGE)) av_log(avctx, AV_LOG_ERROR, "IEND without all image\n"); if (!(s->state & (PNG_ALLIMAGE|PNG_IDAT))) { ret = AVERROR_INVALIDDATA; goto fail; } bytestream2_skip(&s->gb, 4); /* crc */ goto exit_loop; default: /* skip tag */ skip_tag: bytestream2_skip(&s->gb, length + 4); break; } } exit_loop: if (s->bits_per_pixel <= 4) handle_small_bpp(s, p); /* apply transparency if needed */ if (s->has_trns && s->color_type != PNG_COLOR_TYPE_PALETTE) { size_t byte_depth = s->bit_depth > 8 ? 2 : 1; size_t raw_bpp = s->bpp - byte_depth; unsigned x, y; for (y = 0; y < s->height; ++y) { uint8_t *row = &s->image_buf[s->image_linesize * y]; /* since we're updating in-place, we have to go from right to left */ for (x = s->width; x > 0; --x) { uint8_t *pixel = &row[s->bpp * (x - 1)]; memmove(pixel, &row[raw_bpp * (x - 1)], raw_bpp); if (!memcmp(pixel, s->transparent_color_be, raw_bpp)) { memset(&pixel[raw_bpp], 0, byte_depth); } else { memset(&pixel[raw_bpp], 0xff, byte_depth); } } } } /* handle p-frames only if a predecessor frame is available */ if (s->last_picture.f->data[0]) { if ( !(avpkt->flags & AV_PKT_FLAG_KEY) && avctx->codec_tag != AV_RL32("MPNG") && s->last_picture.f->width == p->width && s->last_picture.f->height== p->height && s->last_picture.f->format== p->format ) { if (CONFIG_PNG_DECODER && avctx->codec_id != AV_CODEC_ID_APNG) handle_p_frame_png(s, p); else if (CONFIG_APNG_DECODER && avctx->codec_id == AV_CODEC_ID_APNG && (ret = handle_p_frame_apng(avctx, s, p)) < 0) goto fail; } } ff_thread_report_progress(&s->picture, INT_MAX, 0); av_frame_set_metadata(p, metadata); metadata = NULL; return 0; fail: av_dict_free(&metadata); ff_thread_report_progress(&s->picture, INT_MAX, 0); return ret; } #if CONFIG_PNG_DECODER static int decode_frame_png(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { PNGDecContext *const s = avctx->priv_data; const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; AVFrame *p; int64_t sig; int ret; ff_thread_release_buffer(avctx, &s->last_picture); FFSWAP(ThreadFrame, s->picture, s->last_picture); p = s->picture.f; bytestream2_init(&s->gb, buf, buf_size); /* check signature */ sig = bytestream2_get_be64(&s->gb); if (sig != PNGSIG && sig != MNGSIG) { av_log(avctx, AV_LOG_ERROR, "Invalid PNG signature 0x%08"PRIX64".\n", sig); return AVERROR_INVALIDDATA; } s->y = s->state = s->has_trns = 0; /* init the zlib */ s->zstream.zalloc = ff_png_zalloc; s->zstream.zfree = ff_png_zfree; s->zstream.opaque = NULL; ret = inflateInit(&s->zstream); if (ret != Z_OK) { av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret); return AVERROR_EXTERNAL; } if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0) goto the_end; if ((ret = av_frame_ref(data, s->picture.f)) < 0) return ret; *got_frame = 1; ret = bytestream2_tell(&s->gb); the_end: inflateEnd(&s->zstream); s->crow_buf = NULL; return ret; } #endif #if CONFIG_APNG_DECODER static int decode_frame_apng(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { PNGDecContext *const s = avctx->priv_data; int ret; AVFrame *p; ff_thread_release_buffer(avctx, &s->last_picture); FFSWAP(ThreadFrame, s->picture, s->last_picture); p = s->picture.f; if (!(s->state & PNG_IHDR)) { if (!avctx->extradata_size) return AVERROR_INVALIDDATA; /* only init fields, there is no zlib use in extradata */ s->zstream.zalloc = ff_png_zalloc; s->zstream.zfree = ff_png_zfree; bytestream2_init(&s->gb, avctx->extradata, avctx->extradata_size); if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0) goto end; } /* reset state for a new frame */ if ((ret = inflateInit(&s->zstream)) != Z_OK) { av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret); ret = AVERROR_EXTERNAL; goto end; } s->y = 0; s->state &= ~(PNG_IDAT | PNG_ALLIMAGE); bytestream2_init(&s->gb, avpkt->data, avpkt->size); if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0) goto end; if (!(s->state & PNG_ALLIMAGE)) av_log(avctx, AV_LOG_WARNING, "Frame did not contain a complete image\n"); if (!(s->state & (PNG_ALLIMAGE|PNG_IDAT))) { ret = AVERROR_INVALIDDATA; goto end; } if ((ret = av_frame_ref(data, s->picture.f)) < 0) goto end; *got_frame = 1; ret = bytestream2_tell(&s->gb); end: inflateEnd(&s->zstream); return ret; } #endif static int update_thread_context(AVCodecContext *dst, const AVCodecContext *src) { PNGDecContext *psrc = src->priv_data; PNGDecContext *pdst = dst->priv_data; int ret; if (dst == src) return 0; ff_thread_release_buffer(dst, &pdst->picture); if (psrc->picture.f->data[0] && (ret = ff_thread_ref_frame(&pdst->picture, &psrc->picture)) < 0) return ret; if (CONFIG_APNG_DECODER && dst->codec_id == AV_CODEC_ID_APNG) { pdst->width = psrc->width; pdst->height = psrc->height; pdst->bit_depth = psrc->bit_depth; pdst->color_type = psrc->color_type; pdst->compression_type = psrc->compression_type; pdst->interlace_type = psrc->interlace_type; pdst->filter_type = psrc->filter_type; pdst->cur_w = psrc->cur_w; pdst->cur_h = psrc->cur_h; pdst->x_offset = psrc->x_offset; pdst->y_offset = psrc->y_offset; pdst->has_trns = psrc->has_trns; memcpy(pdst->transparent_color_be, psrc->transparent_color_be, sizeof(pdst->transparent_color_be)); pdst->dispose_op = psrc->dispose_op; memcpy(pdst->palette, psrc->palette, sizeof(pdst->palette)); pdst->state |= psrc->state & (PNG_IHDR | PNG_PLTE); ff_thread_release_buffer(dst, &pdst->last_picture); if (psrc->last_picture.f->data[0] && (ret = ff_thread_ref_frame(&pdst->last_picture, &psrc->last_picture)) < 0) return ret; ff_thread_release_buffer(dst, &pdst->previous_picture); if (psrc->previous_picture.f->data[0] && (ret = ff_thread_ref_frame(&pdst->previous_picture, &psrc->previous_picture)) < 0) return ret; } return 0; } static av_cold int png_dec_init(AVCodecContext *avctx) { PNGDecContext *s = avctx->priv_data; avctx->color_range = AVCOL_RANGE_JPEG; s->avctx = avctx; s->previous_picture.f = av_frame_alloc(); s->last_picture.f = av_frame_alloc(); s->picture.f = av_frame_alloc(); if (!s->previous_picture.f || !s->last_picture.f || !s->picture.f) { av_frame_free(&s->previous_picture.f); av_frame_free(&s->last_picture.f); av_frame_free(&s->picture.f); return AVERROR(ENOMEM); } if (!avctx->internal->is_copy) { avctx->internal->allocate_progress = 1; ff_pngdsp_init(&s->dsp); } return 0; } static av_cold int png_dec_end(AVCodecContext *avctx) { PNGDecContext *s = avctx->priv_data; ff_thread_release_buffer(avctx, &s->previous_picture); av_frame_free(&s->previous_picture.f); 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); av_freep(&s->buffer); s->buffer_size = 0; av_freep(&s->last_row); s->last_row_size = 0; av_freep(&s->tmp_row); s->tmp_row_size = 0; return 0; } #if CONFIG_APNG_DECODER AVCodec ff_apng_decoder = { .name = "apng", .long_name = NULL_IF_CONFIG_SMALL("APNG (Animated Portable Network Graphics) image"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_APNG, .priv_data_size = sizeof(PNGDecContext), .init = png_dec_init, .close = png_dec_end, .decode = decode_frame_apng, .init_thread_copy = ONLY_IF_THREADS_ENABLED(png_dec_init), .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context), .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/, }; #endif #if CONFIG_PNG_DECODER AVCodec ff_png_decoder = { .name = "png", .long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_PNG, .priv_data_size = sizeof(PNGDecContext), .init = png_dec_init, .close = png_dec_end, .decode = decode_frame_png, .init_thread_copy = ONLY_IF_THREADS_ENABLED(png_dec_init), .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context), .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS /*| AV_CODEC_CAP_DRAW_HORIZ_BAND*/, }; #endif