/* * 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/bprint.h" #include "libavutil/imgutils.h" #include "avcodec.h" #include "bytestream.h" #include "internal.h" #include "png.h" #include "pngdsp.h" /* TODO: * - add 16 bit depth support */ #include <zlib.h> typedef struct PNGDecContext { PNGDSPContext dsp; AVCodecContext *avctx; GetByteContext gb; AVFrame *prev; 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; uint8_t *tmp_row; 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) { int 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 == 4 ? size : size - 3; dsp->add_paeth_prediction(dst + i, src + i, last + i, w - 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; 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->height) { 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; 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); 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) { 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->width); 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; } } 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_frame(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 = data; AVDictionary *metadata = NULL; uint8_t *crow_buf_base = NULL; uint32_t tag, length; int64_t sig; int ret; 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, "Missing png signature\n"); return AVERROR_INVALIDDATA; } s->y = s->state = 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; } for (;;) { if (bytestream2_get_bytes_left(&s->gb) <= 0) { av_log(avctx, AV_LOG_ERROR, "No bytes left\n"); 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"); 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 (length != 13) goto fail; s->width = bytestream2_get_be32(&s->gb); s->height = bytestream2_get_be32(&s->gb); if (av_image_check_size(s->width, s->height, 0, avctx)) { s->width = s->height = 0; av_log(avctx, AV_LOG_ERROR, "Invalid image size\n"); goto fail; } 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); break; 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; case MKTAG('I', 'D', 'A', 'T'): if (!(s->state & PNG_IHDR)) { av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n"); goto fail; } 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 = (avctx->width * 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) { 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_Y400A; } else { av_log(avctx, AV_LOG_ERROR, "unsupported bit depth %d " "and color type %d\n", s->bit_depth, s->color_type); goto fail; } if (ff_get_buffer(avctx, p, AV_GET_BUFFER_FLAG_REF) < 0) goto fail; 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->width); s->crow_size = s->pass_row_size + 1; } av_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 */ s->last_row = av_mallocz(s->row_size); if (!s->last_row) goto fail; if (s->interlace_type || s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { s->tmp_row = av_malloc(s->row_size); if (!s->tmp_row) goto fail; } /* compressed row */ crow_buf_base = av_malloc(s->row_size + 16); if (!crow_buf_base) goto fail; /* we want crow_buf+1 to be 16-byte aligned */ s->crow_buf = crow_buf_base + 15; s->zstream.avail_out = s->crow_size; s->zstream.next_out = s->crow_buf; } s->state |= PNG_IDAT; if (png_decode_idat(s, length) < 0) goto fail; bytestream2_skip(&s->gb, 4); /* crc */ 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; 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 */ } 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; for (i = 0; i < length; i++) { v = bytestream2_get_byte(&s->gb); s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24); } bytestream2_skip(&s->gb, 4); /* crc */ } 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))) { 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 == 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; } } 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; } } 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; } } /* handle p-frames only if a predecessor frame is available */ if (s->prev->data[0]) { if ( !(avpkt->flags & AV_PKT_FLAG_KEY) && avctx->codec_tag != AV_RL32("MPNG") && s->prev->width == p->width && s->prev->height== p->height && s->prev->format== p->format ) { int i, j; uint8_t *pd = p->data[0]; uint8_t *pd_last = s->prev->data[0]; for (j = 0; j < s->height; j++) { for (i = 0; i < s->width * s->bpp; i++) { pd[i] += pd_last[i]; } pd += s->image_linesize; pd_last += s->image_linesize; } } } av_frame_set_metadata(p, metadata); metadata = NULL; av_frame_unref(s->prev); if ((ret = av_frame_ref(s->prev, p)) < 0) goto fail; *got_frame = 1; ret = bytestream2_tell(&s->gb); the_end: inflateEnd(&s->zstream); av_free(crow_buf_base); s->crow_buf = NULL; av_freep(&s->last_row); av_freep(&s->tmp_row); return ret; fail: av_dict_free(&metadata); ret = AVERROR_INVALIDDATA; goto the_end; } static av_cold int png_dec_init(AVCodecContext *avctx) { PNGDecContext *s = avctx->priv_data; s->prev = av_frame_alloc(); if (!s->prev) return AVERROR(ENOMEM); ff_pngdsp_init(&s->dsp); s->avctx = avctx; return 0; } static av_cold int png_dec_end(AVCodecContext *avctx) { PNGDecContext *s = avctx->priv_data; av_frame_free(&s->prev); return 0; } AVCodec ff_png_decoder = { .name = "png", .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, .capabilities = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/, .long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"), };