| /* |
| * 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/imgutils.h" |
| #include "avcodec.h" |
| #include "bytestream.h" |
| #include "png.h" |
| |
| /* TODO: |
| * - add 16 bit depth support |
| */ |
| |
| #include <zlib.h> |
| |
| /* 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 = ff_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; |
| } |
| } |
| |
| // 0x7f7f7f7f or 0x7f7f7f7f7f7f7f7f or whatever, depending on the cpu's native arithmetic size |
| #define pb_7f (~0UL/255 * 0x7f) |
| #define pb_80 (~0UL/255 * 0x80) |
| |
| static void add_bytes_l2_c(uint8_t *dst, uint8_t *src1, uint8_t *src2, int w) |
| { |
| long i; |
| for(i=0; i<=w-sizeof(long); i+=sizeof(long)){ |
| long a = *(long*)(src1+i); |
| long b = *(long*)(src2+i); |
| *(long*)(dst+i) = ((a&pb_7f) + (b&pb_7f)) ^ ((a^b)&pb_80); |
| } |
| for(; i<w; i++) |
| dst[i] = src1[i]+src2[i]; |
| } |
| |
| static void add_paeth_prediction_c(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; 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)\ |
| else {\ |
| for (; i < size; i += bpp) {\ |
| int j;\ |
| for (j = 0; j < bpp; j++)\ |
| dst[i+j] = op(dst[i+j-bpp], src[i+j], last[i+j]);\ |
| }\ |
| } |
| |
| /* NOTE: 'dst' can be equal to 'last' */ |
| static void png_filter_row(PNGDecContext *s, 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: |
| s->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; |
| s->add_paeth_prediction(dst+i, src+i, last+i, w-i, bpp); |
| i = w; |
| } |
| add_paeth_prediction_c(dst+i, src+i, last+i, size-i, bpp); |
| break; |
| } |
| } |
| |
| static av_always_inline void convert_to_rgb32_loco(uint8_t *dst, const uint8_t *src, int width, int loco) |
| { |
| int j; |
| unsigned int r, g, b, a; |
| |
| for(j = 0;j < width; j++) { |
| r = src[0]; |
| g = src[1]; |
| b = src[2]; |
| a = src[3]; |
| if(loco) { |
| r = (r+g)&0xff; |
| b = (b+g)&0xff; |
| } |
| dst[0] = r; |
| dst[1] = g; |
| dst[2] = b; |
| dst[3] = a; |
| dst += 4; |
| src += 4; |
| } |
| } |
| |
| static void convert_to_rgb32(uint8_t *dst, const uint8_t *src, int width, int loco) |
| { |
| if(loco) |
| convert_to_rgb32_loco(dst, src, width, 1); |
| else |
| memcpy(dst, src, width * 4); |
| } |
| |
| static void deloco_rgb24(uint8_t *dst, int size) |
| { |
| int i; |
| for(i=0; i<size; i+=3) { |
| int g = dst[i+1]; |
| dst[i+0] += g; |
| dst[i+2] += g; |
| } |
| } |
| |
| /* 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; |
| /* need to swap bytes correctly for RGB_ALPHA */ |
| if (s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { |
| png_filter_row(s, s->tmp_row, s->crow_buf[0], s->crow_buf + 1, |
| s->last_row, s->row_size, s->bpp); |
| convert_to_rgb32(ptr, s->tmp_row, s->width, s->filter_type == PNG_FILTER_TYPE_LOCO); |
| FFSWAP(uint8_t*, s->last_row, s->tmp_row); |
| } else { |
| /* in normal case, we avoid one copy */ |
| if (s->y == 0) |
| last_row = s->last_row; |
| else |
| last_row = ptr - s->image_linesize; |
| |
| png_filter_row(s, 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->color_type == PNG_COLOR_TYPE_RGB && s->y > 0) |
| deloco_rgb24(ptr - s->image_linesize, s->row_size); |
| s->y++; |
| if (s->y == s->height) { |
| s->state |= PNG_ALLIMAGE; |
| if (s->filter_type == PNG_FILTER_TYPE_LOCO && |
| s->color_type == PNG_COLOR_TYPE_RGB) |
| deloco_rgb24(ptr, s->row_size); |
| } |
| } 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, 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 = 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) { |
| 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_frame(AVCodecContext *avctx, |
| void *data, int *data_size, |
| AVPacket *avpkt) |
| { |
| const uint8_t *buf = avpkt->data; |
| int buf_size = avpkt->size; |
| PNGDecContext * const s = avctx->priv_data; |
| AVFrame *picture = data; |
| AVFrame *p; |
| uint8_t *crow_buf_base = NULL; |
| uint32_t tag, length; |
| int ret; |
| |
| FFSWAP(AVFrame *, s->current_picture, s->last_picture); |
| avctx->coded_frame= s->current_picture; |
| p = s->current_picture; |
| |
| /* check signature */ |
| if (buf_size < 8 || |
| memcmp(buf, ff_pngsig, 8) != 0 && |
| memcmp(buf, ff_mngsig, 8) != 0) |
| return -1; |
| |
| bytestream2_init(&s->gb, buf + 8, buf_size - 8); |
| s->y= |
| s->state=0; |
| // memset(s, 0, sizeof(PNGDecContext)); |
| /* 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) |
| return -1; |
| for(;;) { |
| if (bytestream2_get_bytes_left(&s->gb) <= 0) |
| goto fail; |
| length = bytestream2_get_be32(&s->gb); |
| if (length > 0x7fffffff) |
| 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; |
| 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('I', 'D', 'A', 'T'): |
| if (!(s->state & PNG_IHDR)) |
| 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 == 8 && |
| s->color_type == PNG_COLOR_TYPE_RGB) { |
| avctx->pix_fmt = PIX_FMT_RGB24; |
| } else if (s->bit_depth == 8 && |
| s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { |
| avctx->pix_fmt = PIX_FMT_RGBA; |
| } else if (s->bit_depth == 8 && |
| s->color_type == PNG_COLOR_TYPE_GRAY) { |
| avctx->pix_fmt = PIX_FMT_GRAY8; |
| } else if (s->bit_depth == 16 && |
| s->color_type == PNG_COLOR_TYPE_GRAY) { |
| avctx->pix_fmt = PIX_FMT_GRAY16BE; |
| } else if (s->bit_depth == 16 && |
| s->color_type == PNG_COLOR_TYPE_RGB) { |
| avctx->pix_fmt = PIX_FMT_RGB48BE; |
| } 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 = PIX_FMT_PAL8; |
| } else if (s->bit_depth == 1) { |
| avctx->pix_fmt = PIX_FMT_MONOBLACK; |
| } else if (s->bit_depth == 8 && |
| s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) { |
| avctx->pix_fmt = 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(p->data[0]) |
| avctx->release_buffer(avctx, p); |
| |
| p->reference= 3; |
| if(avctx->get_buffer(avctx, p) < 0){ |
| av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); |
| 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 == 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] = (0xff << 24) | (r << 16) | (g << 8) | b; |
| } |
| for(;i<256;i++) { |
| s->palette[i] = (0xff << 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('I', 'E', 'N', 'D'): |
| if (!(s->state & PNG_ALLIMAGE)) |
| 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; |
| uint8_t *pd = s->current_picture->data[0]; |
| for(j=0; j < s->height; j++) { |
| for(i=s->width/8-1; 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 = s->current_picture->data[0]; |
| for(j=0; j < s->height; j++) { |
| for(i=s->width/4-1; 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; |
| } |
| pd += s->image_linesize; |
| } |
| } |
| if(s->bits_per_pixel == 4){ |
| int i, j; |
| uint8_t *pd = s->current_picture->data[0]; |
| for(j=0; j < s->height; j++) { |
| for(i=s->width/2-1; i>=0; i--) { |
| pd[2*i+1]= pd[i]&15; |
| pd[2*i+0]= pd[i]>>4; |
| } |
| pd += s->image_linesize; |
| } |
| } |
| |
| /* handle p-frames only if a predecessor frame is available */ |
| if(s->last_picture->data[0] != NULL) { |
| if(!(avpkt->flags & AV_PKT_FLAG_KEY)) { |
| int i, j; |
| uint8_t *pd = s->current_picture->data[0]; |
| uint8_t *pd_last = s->last_picture->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; |
| } |
| } |
| } |
| |
| *picture= *s->current_picture; |
| *data_size = sizeof(AVFrame); |
| |
| 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: |
| ret = -1; |
| goto the_end; |
| } |
| |
| static av_cold int png_dec_init(AVCodecContext *avctx) |
| { |
| PNGDecContext *s = avctx->priv_data; |
| |
| s->current_picture = &s->picture1; |
| s->last_picture = &s->picture2; |
| avcodec_get_frame_defaults(&s->picture1); |
| avcodec_get_frame_defaults(&s->picture2); |
| |
| #if HAVE_MMX |
| ff_png_init_mmx(s); |
| #endif |
| |
| if (!s->add_paeth_prediction) |
| s->add_paeth_prediction = add_paeth_prediction_c; |
| if (!s->add_bytes_l2) |
| s->add_bytes_l2 = add_bytes_l2_c; |
| |
| return 0; |
| } |
| |
| static av_cold int png_dec_end(AVCodecContext *avctx) |
| { |
| PNGDecContext *s = avctx->priv_data; |
| |
| if (s->picture1.data[0]) |
| avctx->release_buffer(avctx, &s->picture1); |
| if (s->picture2.data[0]) |
| avctx->release_buffer(avctx, &s->picture2); |
| |
| return 0; |
| } |
| |
| AVCodec ff_png_decoder = { |
| .name = "png", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .id = 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 image"), |
| }; |
