diff options
Diffstat (limited to 'ffmpeg/libavcodec/pngdec.c')
| -rw-r--r-- | ffmpeg/libavcodec/pngdec.c | 902 |
1 files changed, 902 insertions, 0 deletions
diff --git a/ffmpeg/libavcodec/pngdec.c b/ffmpeg/libavcodec/pngdec.c new file mode 100644 index 0000000..086f3b4 --- /dev/null +++ b/ffmpeg/libavcodec/pngdec.c @@ -0,0 +1,902 @@ +/* + * 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> + +//#define DEBUG + +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 %d\n", ret); + return -1; + } + 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 -1; + } + + 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 %d\n", ret); + return -1; + } + 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) + && 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 = -1; + 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"), +}; |