Libav 0.7.1
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00001 /* 00002 * PNG image format 00003 * Copyright (c) 2003 Fabrice Bellard 00004 * 00005 * This file is part of Libav. 00006 * 00007 * Libav is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * Libav is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with Libav; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 #include "libavutil/imgutils.h" 00022 #include "avcodec.h" 00023 #include "bytestream.h" 00024 #include "png.h" 00025 #include "dsputil.h" 00026 00027 /* TODO: 00028 * - add 2, 4 and 16 bit depth support 00029 */ 00030 00031 #include <zlib.h> 00032 00033 //#define DEBUG 00034 00035 typedef struct PNGDecContext { 00036 DSPContext dsp; 00037 00038 const uint8_t *bytestream; 00039 const uint8_t *bytestream_start; 00040 const uint8_t *bytestream_end; 00041 AVFrame picture1, picture2; 00042 AVFrame *current_picture, *last_picture; 00043 00044 int state; 00045 int width, height; 00046 int bit_depth; 00047 int color_type; 00048 int compression_type; 00049 int interlace_type; 00050 int filter_type; 00051 int channels; 00052 int bits_per_pixel; 00053 int bpp; 00054 00055 uint8_t *image_buf; 00056 int image_linesize; 00057 uint32_t palette[256]; 00058 uint8_t *crow_buf; 00059 uint8_t *last_row; 00060 uint8_t *tmp_row; 00061 int pass; 00062 int crow_size; /* compressed row size (include filter type) */ 00063 int row_size; /* decompressed row size */ 00064 int pass_row_size; /* decompress row size of the current pass */ 00065 int y; 00066 z_stream zstream; 00067 } PNGDecContext; 00068 00069 /* Mask to determine which y pixels can be written in a pass */ 00070 static const uint8_t png_pass_dsp_ymask[NB_PASSES] = { 00071 0xff, 0xff, 0x0f, 0xcc, 0x33, 0xff, 0x55, 00072 }; 00073 00074 /* Mask to determine which pixels to overwrite while displaying */ 00075 static const uint8_t png_pass_dsp_mask[NB_PASSES] = { 00076 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff 00077 }; 00078 00079 /* NOTE: we try to construct a good looking image at each pass. width 00080 is the original image width. We also do pixel format conversion at 00081 this stage */ 00082 static void png_put_interlaced_row(uint8_t *dst, int width, 00083 int bits_per_pixel, int pass, 00084 int color_type, const uint8_t *src) 00085 { 00086 int x, mask, dsp_mask, j, src_x, b, bpp; 00087 uint8_t *d; 00088 const uint8_t *s; 00089 00090 mask = ff_png_pass_mask[pass]; 00091 dsp_mask = png_pass_dsp_mask[pass]; 00092 switch(bits_per_pixel) { 00093 case 1: 00094 /* we must initialize the line to zero before writing to it */ 00095 if (pass == 0) 00096 memset(dst, 0, (width + 7) >> 3); 00097 src_x = 0; 00098 for(x = 0; x < width; x++) { 00099 j = (x & 7); 00100 if ((dsp_mask << j) & 0x80) { 00101 b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1; 00102 dst[x >> 3] |= b << (7 - j); 00103 } 00104 if ((mask << j) & 0x80) 00105 src_x++; 00106 } 00107 break; 00108 default: 00109 bpp = bits_per_pixel >> 3; 00110 d = dst; 00111 s = src; 00112 if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) { 00113 for(x = 0; x < width; x++) { 00114 j = x & 7; 00115 if ((dsp_mask << j) & 0x80) { 00116 *(uint32_t *)d = (s[3] << 24) | (s[0] << 16) | (s[1] << 8) | s[2]; 00117 } 00118 d += bpp; 00119 if ((mask << j) & 0x80) 00120 s += bpp; 00121 } 00122 } else { 00123 for(x = 0; x < width; x++) { 00124 j = x & 7; 00125 if ((dsp_mask << j) & 0x80) { 00126 memcpy(d, s, bpp); 00127 } 00128 d += bpp; 00129 if ((mask << j) & 0x80) 00130 s += bpp; 00131 } 00132 } 00133 break; 00134 } 00135 } 00136 00137 void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp) 00138 { 00139 int i; 00140 for(i = 0; i < w; i++) { 00141 int a, b, c, p, pa, pb, pc; 00142 00143 a = dst[i - bpp]; 00144 b = top[i]; 00145 c = top[i - bpp]; 00146 00147 p = b - c; 00148 pc = a - c; 00149 00150 pa = abs(p); 00151 pb = abs(pc); 00152 pc = abs(p + pc); 00153 00154 if (pa <= pb && pa <= pc) 00155 p = a; 00156 else if (pb <= pc) 00157 p = b; 00158 else 00159 p = c; 00160 dst[i] = p + src[i]; 00161 } 00162 } 00163 00164 #define UNROLL1(bpp, op) {\ 00165 r = dst[0];\ 00166 if(bpp >= 2) g = dst[1];\ 00167 if(bpp >= 3) b = dst[2];\ 00168 if(bpp >= 4) a = dst[3];\ 00169 for(; i < size; i+=bpp) {\ 00170 dst[i+0] = r = op(r, src[i+0], last[i+0]);\ 00171 if(bpp == 1) continue;\ 00172 dst[i+1] = g = op(g, src[i+1], last[i+1]);\ 00173 if(bpp == 2) continue;\ 00174 dst[i+2] = b = op(b, src[i+2], last[i+2]);\ 00175 if(bpp == 3) continue;\ 00176 dst[i+3] = a = op(a, src[i+3], last[i+3]);\ 00177 }\ 00178 } 00179 00180 #define UNROLL_FILTER(op)\ 00181 if(bpp == 1) UNROLL1(1, op)\ 00182 else if(bpp == 2) UNROLL1(2, op)\ 00183 else if(bpp == 3) UNROLL1(3, op)\ 00184 else if(bpp == 4) UNROLL1(4, op)\ 00185 else {\ 00186 for (; i < size; i += bpp) {\ 00187 int j;\ 00188 for (j = 0; j < bpp; j++)\ 00189 dst[i+j] = op(dst[i+j-bpp], src[i+j], last[i+j]);\ 00190 }\ 00191 } 00192 00193 /* NOTE: 'dst' can be equal to 'last' */ 00194 static void png_filter_row(DSPContext *dsp, uint8_t *dst, int filter_type, 00195 uint8_t *src, uint8_t *last, int size, int bpp) 00196 { 00197 int i, p, r, g, b, a; 00198 00199 switch(filter_type) { 00200 case PNG_FILTER_VALUE_NONE: 00201 memcpy(dst, src, size); 00202 break; 00203 case PNG_FILTER_VALUE_SUB: 00204 for(i = 0; i < bpp; i++) { 00205 dst[i] = src[i]; 00206 } 00207 if(bpp == 4) { 00208 p = *(int*)dst; 00209 for(; i < size; i+=bpp) { 00210 int s = *(int*)(src+i); 00211 p = ((s&0x7f7f7f7f) + (p&0x7f7f7f7f)) ^ ((s^p)&0x80808080); 00212 *(int*)(dst+i) = p; 00213 } 00214 } else { 00215 #define OP_SUB(x,s,l) x+s 00216 UNROLL_FILTER(OP_SUB); 00217 } 00218 break; 00219 case PNG_FILTER_VALUE_UP: 00220 dsp->add_bytes_l2(dst, src, last, size); 00221 break; 00222 case PNG_FILTER_VALUE_AVG: 00223 for(i = 0; i < bpp; i++) { 00224 p = (last[i] >> 1); 00225 dst[i] = p + src[i]; 00226 } 00227 #define OP_AVG(x,s,l) (((x + l) >> 1) + s) & 0xff 00228 UNROLL_FILTER(OP_AVG); 00229 break; 00230 case PNG_FILTER_VALUE_PAETH: 00231 for(i = 0; i < bpp; i++) { 00232 p = last[i]; 00233 dst[i] = p + src[i]; 00234 } 00235 if(bpp > 1 && size > 4) { 00236 // would write off the end of the array if we let it process the last pixel with bpp=3 00237 int w = bpp==4 ? size : size-3; 00238 dsp->add_png_paeth_prediction(dst+i, src+i, last+i, w-i, bpp); 00239 i = w; 00240 } 00241 ff_add_png_paeth_prediction(dst+i, src+i, last+i, size-i, bpp); 00242 break; 00243 } 00244 } 00245 00246 static av_always_inline void convert_to_rgb32_loco(uint8_t *dst, const uint8_t *src, int width, int loco) 00247 { 00248 int j; 00249 unsigned int r, g, b, a; 00250 00251 for(j = 0;j < width; j++) { 00252 r = src[0]; 00253 g = src[1]; 00254 b = src[2]; 00255 a = src[3]; 00256 if(loco) { 00257 r = (r+g)&0xff; 00258 b = (b+g)&0xff; 00259 } 00260 *(uint32_t *)dst = (a << 24) | (r << 16) | (g << 8) | b; 00261 dst += 4; 00262 src += 4; 00263 } 00264 } 00265 00266 static void convert_to_rgb32(uint8_t *dst, const uint8_t *src, int width, int loco) 00267 { 00268 if(loco) 00269 convert_to_rgb32_loco(dst, src, width, 1); 00270 else 00271 convert_to_rgb32_loco(dst, src, width, 0); 00272 } 00273 00274 static void deloco_rgb24(uint8_t *dst, int size) 00275 { 00276 int i; 00277 for(i=0; i<size; i+=3) { 00278 int g = dst[i+1]; 00279 dst[i+0] += g; 00280 dst[i+2] += g; 00281 } 00282 } 00283 00284 /* process exactly one decompressed row */ 00285 static void png_handle_row(PNGDecContext *s) 00286 { 00287 uint8_t *ptr, *last_row; 00288 int got_line; 00289 00290 if (!s->interlace_type) { 00291 ptr = s->image_buf + s->image_linesize * s->y; 00292 /* need to swap bytes correctly for RGB_ALPHA */ 00293 if (s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { 00294 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1, 00295 s->last_row, s->row_size, s->bpp); 00296 convert_to_rgb32(ptr, s->tmp_row, s->width, s->filter_type == PNG_FILTER_TYPE_LOCO); 00297 FFSWAP(uint8_t*, s->last_row, s->tmp_row); 00298 } else { 00299 /* in normal case, we avoid one copy */ 00300 if (s->y == 0) 00301 last_row = s->last_row; 00302 else 00303 last_row = ptr - s->image_linesize; 00304 00305 png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1, 00306 last_row, s->row_size, s->bpp); 00307 } 00308 /* loco lags by 1 row so that it doesn't interfere with top prediction */ 00309 if (s->filter_type == PNG_FILTER_TYPE_LOCO && 00310 s->color_type == PNG_COLOR_TYPE_RGB && s->y > 0) 00311 deloco_rgb24(ptr - s->image_linesize, s->row_size); 00312 s->y++; 00313 if (s->y == s->height) { 00314 s->state |= PNG_ALLIMAGE; 00315 if (s->filter_type == PNG_FILTER_TYPE_LOCO && 00316 s->color_type == PNG_COLOR_TYPE_RGB) 00317 deloco_rgb24(ptr, s->row_size); 00318 } 00319 } else { 00320 got_line = 0; 00321 for(;;) { 00322 ptr = s->image_buf + s->image_linesize * s->y; 00323 if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) { 00324 /* if we already read one row, it is time to stop to 00325 wait for the next one */ 00326 if (got_line) 00327 break; 00328 png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1, 00329 s->last_row, s->pass_row_size, s->bpp); 00330 FFSWAP(uint8_t*, s->last_row, s->tmp_row); 00331 got_line = 1; 00332 } 00333 if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) { 00334 /* NOTE: RGB32 is handled directly in png_put_interlaced_row */ 00335 png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass, 00336 s->color_type, s->last_row); 00337 } 00338 s->y++; 00339 if (s->y == s->height) { 00340 for(;;) { 00341 if (s->pass == NB_PASSES - 1) { 00342 s->state |= PNG_ALLIMAGE; 00343 goto the_end; 00344 } else { 00345 s->pass++; 00346 s->y = 0; 00347 s->pass_row_size = ff_png_pass_row_size(s->pass, 00348 s->bits_per_pixel, 00349 s->width); 00350 s->crow_size = s->pass_row_size + 1; 00351 if (s->pass_row_size != 0) 00352 break; 00353 /* skip pass if empty row */ 00354 } 00355 } 00356 } 00357 } 00358 the_end: ; 00359 } 00360 } 00361 00362 static int png_decode_idat(PNGDecContext *s, int length) 00363 { 00364 int ret; 00365 s->zstream.avail_in = length; 00366 s->zstream.next_in = s->bytestream; 00367 s->bytestream += length; 00368 00369 if(s->bytestream > s->bytestream_end) 00370 return -1; 00371 00372 /* decode one line if possible */ 00373 while (s->zstream.avail_in > 0) { 00374 ret = inflate(&s->zstream, Z_PARTIAL_FLUSH); 00375 if (ret != Z_OK && ret != Z_STREAM_END) { 00376 return -1; 00377 } 00378 if (s->zstream.avail_out == 0) { 00379 if (!(s->state & PNG_ALLIMAGE)) { 00380 png_handle_row(s); 00381 } 00382 s->zstream.avail_out = s->crow_size; 00383 s->zstream.next_out = s->crow_buf; 00384 } 00385 } 00386 return 0; 00387 } 00388 00389 static int decode_frame(AVCodecContext *avctx, 00390 void *data, int *data_size, 00391 AVPacket *avpkt) 00392 { 00393 const uint8_t *buf = avpkt->data; 00394 int buf_size = avpkt->size; 00395 PNGDecContext * const s = avctx->priv_data; 00396 AVFrame *picture = data; 00397 AVFrame *p; 00398 uint8_t *crow_buf_base = NULL; 00399 uint32_t tag, length; 00400 int ret; 00401 00402 FFSWAP(AVFrame *, s->current_picture, s->last_picture); 00403 avctx->coded_frame= s->current_picture; 00404 p = s->current_picture; 00405 00406 s->bytestream_start= 00407 s->bytestream= buf; 00408 s->bytestream_end= buf + buf_size; 00409 00410 /* check signature */ 00411 if (memcmp(s->bytestream, ff_pngsig, 8) != 0 && 00412 memcmp(s->bytestream, ff_mngsig, 8) != 0) 00413 return -1; 00414 s->bytestream+= 8; 00415 s->y= 00416 s->state=0; 00417 // memset(s, 0, sizeof(PNGDecContext)); 00418 /* init the zlib */ 00419 s->zstream.zalloc = ff_png_zalloc; 00420 s->zstream.zfree = ff_png_zfree; 00421 s->zstream.opaque = NULL; 00422 ret = inflateInit(&s->zstream); 00423 if (ret != Z_OK) 00424 return -1; 00425 for(;;) { 00426 int tag32; 00427 if (s->bytestream >= s->bytestream_end) 00428 goto fail; 00429 length = bytestream_get_be32(&s->bytestream); 00430 if (length > 0x7fffffff) 00431 goto fail; 00432 tag32 = bytestream_get_be32(&s->bytestream); 00433 tag = av_bswap32(tag32); 00434 av_dlog(avctx, "png: tag=%c%c%c%c length=%u\n", 00435 (tag & 0xff), 00436 ((tag >> 8) & 0xff), 00437 ((tag >> 16) & 0xff), 00438 ((tag >> 24) & 0xff), length); 00439 switch(tag) { 00440 case MKTAG('I', 'H', 'D', 'R'): 00441 if (length != 13) 00442 goto fail; 00443 s->width = bytestream_get_be32(&s->bytestream); 00444 s->height = bytestream_get_be32(&s->bytestream); 00445 if(av_image_check_size(s->width, s->height, 0, avctx)){ 00446 s->width= s->height= 0; 00447 goto fail; 00448 } 00449 s->bit_depth = *s->bytestream++; 00450 s->color_type = *s->bytestream++; 00451 s->compression_type = *s->bytestream++; 00452 s->filter_type = *s->bytestream++; 00453 s->interlace_type = *s->bytestream++; 00454 s->bytestream += 4; /* crc */ 00455 s->state |= PNG_IHDR; 00456 av_dlog(avctx, "width=%d height=%d depth=%d color_type=%d compression_type=%d filter_type=%d interlace_type=%d\n", 00457 s->width, s->height, s->bit_depth, s->color_type, 00458 s->compression_type, s->filter_type, s->interlace_type); 00459 break; 00460 case MKTAG('I', 'D', 'A', 'T'): 00461 if (!(s->state & PNG_IHDR)) 00462 goto fail; 00463 if (!(s->state & PNG_IDAT)) { 00464 /* init image info */ 00465 avctx->width = s->width; 00466 avctx->height = s->height; 00467 00468 s->channels = ff_png_get_nb_channels(s->color_type); 00469 s->bits_per_pixel = s->bit_depth * s->channels; 00470 s->bpp = (s->bits_per_pixel + 7) >> 3; 00471 s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3; 00472 00473 if (s->bit_depth == 8 && 00474 s->color_type == PNG_COLOR_TYPE_RGB) { 00475 avctx->pix_fmt = PIX_FMT_RGB24; 00476 } else if (s->bit_depth == 8 && 00477 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { 00478 avctx->pix_fmt = PIX_FMT_RGB32; 00479 } else if (s->bit_depth == 8 && 00480 s->color_type == PNG_COLOR_TYPE_GRAY) { 00481 avctx->pix_fmt = PIX_FMT_GRAY8; 00482 } else if (s->bit_depth == 16 && 00483 s->color_type == PNG_COLOR_TYPE_GRAY) { 00484 avctx->pix_fmt = PIX_FMT_GRAY16BE; 00485 } else if (s->bit_depth == 16 && 00486 s->color_type == PNG_COLOR_TYPE_RGB) { 00487 avctx->pix_fmt = PIX_FMT_RGB48BE; 00488 } else if (s->bit_depth == 1 && 00489 s->color_type == PNG_COLOR_TYPE_GRAY) { 00490 avctx->pix_fmt = PIX_FMT_MONOBLACK; 00491 } else if (s->color_type == PNG_COLOR_TYPE_PALETTE) { 00492 avctx->pix_fmt = PIX_FMT_PAL8; 00493 } else if (s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) { 00494 avctx->pix_fmt = PIX_FMT_Y400A; 00495 } else { 00496 goto fail; 00497 } 00498 if(p->data[0]) 00499 avctx->release_buffer(avctx, p); 00500 00501 p->reference= 0; 00502 if(avctx->get_buffer(avctx, p) < 0){ 00503 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 00504 goto fail; 00505 } 00506 p->pict_type= AV_PICTURE_TYPE_I; 00507 p->key_frame= 1; 00508 p->interlaced_frame = !!s->interlace_type; 00509 00510 /* compute the compressed row size */ 00511 if (!s->interlace_type) { 00512 s->crow_size = s->row_size + 1; 00513 } else { 00514 s->pass = 0; 00515 s->pass_row_size = ff_png_pass_row_size(s->pass, 00516 s->bits_per_pixel, 00517 s->width); 00518 s->crow_size = s->pass_row_size + 1; 00519 } 00520 av_dlog(avctx, "row_size=%d crow_size =%d\n", 00521 s->row_size, s->crow_size); 00522 s->image_buf = p->data[0]; 00523 s->image_linesize = p->linesize[0]; 00524 /* copy the palette if needed */ 00525 if (s->color_type == PNG_COLOR_TYPE_PALETTE) 00526 memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t)); 00527 /* empty row is used if differencing to the first row */ 00528 s->last_row = av_mallocz(s->row_size); 00529 if (!s->last_row) 00530 goto fail; 00531 if (s->interlace_type || 00532 s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { 00533 s->tmp_row = av_malloc(s->row_size); 00534 if (!s->tmp_row) 00535 goto fail; 00536 } 00537 /* compressed row */ 00538 crow_buf_base = av_malloc(s->row_size + 16); 00539 if (!crow_buf_base) 00540 goto fail; 00541 00542 /* we want crow_buf+1 to be 16-byte aligned */ 00543 s->crow_buf = crow_buf_base + 15; 00544 s->zstream.avail_out = s->crow_size; 00545 s->zstream.next_out = s->crow_buf; 00546 } 00547 s->state |= PNG_IDAT; 00548 if (png_decode_idat(s, length) < 0) 00549 goto fail; 00550 s->bytestream += 4; /* crc */ 00551 break; 00552 case MKTAG('P', 'L', 'T', 'E'): 00553 { 00554 int n, i, r, g, b; 00555 00556 if ((length % 3) != 0 || length > 256 * 3) 00557 goto skip_tag; 00558 /* read the palette */ 00559 n = length / 3; 00560 for(i=0;i<n;i++) { 00561 r = *s->bytestream++; 00562 g = *s->bytestream++; 00563 b = *s->bytestream++; 00564 s->palette[i] = (0xff << 24) | (r << 16) | (g << 8) | b; 00565 } 00566 for(;i<256;i++) { 00567 s->palette[i] = (0xff << 24); 00568 } 00569 s->state |= PNG_PLTE; 00570 s->bytestream += 4; /* crc */ 00571 } 00572 break; 00573 case MKTAG('t', 'R', 'N', 'S'): 00574 { 00575 int v, i; 00576 00577 /* read the transparency. XXX: Only palette mode supported */ 00578 if (s->color_type != PNG_COLOR_TYPE_PALETTE || 00579 length > 256 || 00580 !(s->state & PNG_PLTE)) 00581 goto skip_tag; 00582 for(i=0;i<length;i++) { 00583 v = *s->bytestream++; 00584 s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24); 00585 } 00586 s->bytestream += 4; /* crc */ 00587 } 00588 break; 00589 case MKTAG('I', 'E', 'N', 'D'): 00590 if (!(s->state & PNG_ALLIMAGE)) 00591 goto fail; 00592 s->bytestream += 4; /* crc */ 00593 goto exit_loop; 00594 default: 00595 /* skip tag */ 00596 skip_tag: 00597 s->bytestream += length + 4; 00598 break; 00599 } 00600 } 00601 exit_loop: 00602 /* handle p-frames only if a predecessor frame is available */ 00603 if(s->last_picture->data[0] != NULL) { 00604 if(!(avpkt->flags & AV_PKT_FLAG_KEY)) { 00605 int i, j; 00606 uint8_t *pd = s->current_picture->data[0]; 00607 uint8_t *pd_last = s->last_picture->data[0]; 00608 00609 for(j=0; j < s->height; j++) { 00610 for(i=0; i < s->width * s->bpp; i++) { 00611 pd[i] += pd_last[i]; 00612 } 00613 pd += s->image_linesize; 00614 pd_last += s->image_linesize; 00615 } 00616 } 00617 } 00618 00619 *picture= *s->current_picture; 00620 *data_size = sizeof(AVFrame); 00621 00622 ret = s->bytestream - s->bytestream_start; 00623 the_end: 00624 inflateEnd(&s->zstream); 00625 av_free(crow_buf_base); 00626 s->crow_buf = NULL; 00627 av_freep(&s->last_row); 00628 av_freep(&s->tmp_row); 00629 return ret; 00630 fail: 00631 ret = -1; 00632 goto the_end; 00633 } 00634 00635 static av_cold int png_dec_init(AVCodecContext *avctx){ 00636 PNGDecContext *s = avctx->priv_data; 00637 00638 s->current_picture = &s->picture1; 00639 s->last_picture = &s->picture2; 00640 avcodec_get_frame_defaults(&s->picture1); 00641 avcodec_get_frame_defaults(&s->picture2); 00642 dsputil_init(&s->dsp, avctx); 00643 00644 return 0; 00645 } 00646 00647 static av_cold int png_dec_end(AVCodecContext *avctx) 00648 { 00649 PNGDecContext *s = avctx->priv_data; 00650 00651 if (s->picture1.data[0]) 00652 avctx->release_buffer(avctx, &s->picture1); 00653 if (s->picture2.data[0]) 00654 avctx->release_buffer(avctx, &s->picture2); 00655 00656 return 0; 00657 } 00658 00659 AVCodec ff_png_decoder = { 00660 "png", 00661 AVMEDIA_TYPE_VIDEO, 00662 CODEC_ID_PNG, 00663 sizeof(PNGDecContext), 00664 png_dec_init, 00665 NULL, 00666 png_dec_end, 00667 decode_frame, 00668 CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/, 00669 NULL, 00670 .long_name = NULL_IF_CONFIG_SMALL("PNG image"), 00671 };