libavcodec/pngenc.c

   1 /*
   2  * PNG image format
   3  * Copyright (c) 2003 Fabrice Bellard.
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21 #include "avcodec.h"
  22 #include "bytestream.h"
  23 #include "png.h"
  24
  25 /* TODO:
  26  * - add 2, 4 and 16 bit depth support
  27  * - use filters when generating a png (better compression)
  28  */
  29
  30 #include <zlib.h>
  31
  32 //#define DEBUG
  33
  34 #define IOBUF_SIZE 4096
  35
  36 typedef struct PNGEncContext {
  37     uint8_t *bytestream;
  38     uint8_t *bytestream_start;
  39     uint8_t *bytestream_end;
  40     AVFrame picture;
  41
  42     z_stream zstream;
  43     uint8_t buf[IOBUF_SIZE];
  44 } PNGEncContext;
  45
  46 static void png_get_interlaced_row(uint8_t *dst, int row_size,
  47                                    int bits_per_pixel, int pass,
  48                                    const uint8_t *src, int width)
  49 {
  50     int x, mask, dst_x, j, b, bpp;
  51     uint8_t *d;
  52     const uint8_t *s;
  53
  54     mask = ff_png_pass_mask[pass];
  55     switch(bits_per_pixel) {
  56     case 1:
  57         memset(dst, 0, row_size);
  58         dst_x = 0;
  59         for(x = 0; x < width; x++) {
  60             j = (x & 7);
  61             if ((mask << j) & 0x80) {
  62                 b = (src[x >> 3] >> (7 - j)) & 1;
  63                 dst[dst_x >> 3] |= b << (7 - (dst_x & 7));
  64                 dst_x++;
  65             }
  66         }
  67         break;
  68     default:
  69         bpp = bits_per_pixel >> 3;
  70         d = dst;
  71         s = src;
  72         for(x = 0; x < width; x++) {
  73             j = x & 7;
  74             if ((mask << j) & 0x80) {
  75                 memcpy(d, s, bpp);
  76                 d += bpp;
  77             }
  78             s += bpp;
  79         }
  80         break;
  81     }
  82 }
  83
  84 static void convert_from_rgb32(uint8_t *dst, const uint8_t *src, int width)
  85 {
  86     uint8_t *d;
  87     int j;
  88     unsigned int v;
  89
  90     d = dst;
  91     for(j = 0; j < width; j++) {
  92         v = ((const uint32_t *)src)[j];
  93         d[0] = v >> 16;
  94         d[1] = v >> 8;
  95         d[2] = v;
  96         d[3] = v >> 24;
  97         d += 4;
  98     }
  99 }
 100
 101 static void png_write_chunk(uint8_t **f, uint32_t tag,
 102                             const uint8_t *buf, int length)
 103 {
 104     uint32_t crc;
 105     uint8_t tagbuf[4];
 106
 107     bytestream_put_be32(f, length);
 108     crc = crc32(0, Z_NULL, 0);
 109     AV_WL32(tagbuf, tag);
 110     crc = crc32(crc, tagbuf, 4);
 111     bytestream_put_be32(f, bswap_32(tag));
 112     if (length > 0) {
 113         crc = crc32(crc, buf, length);
 114         memcpy(*f, buf, length);
 115         *f += length;
 116     }
 117     bytestream_put_be32(f, crc);
 118 }
 119
 120 /* XXX: do filtering */
 121 static int png_write_row(PNGEncContext *s, const uint8_t *data, int size)
 122 {
 123     int ret;
 124
 125     s->zstream.avail_in = size;
 126     s->zstream.next_in = (uint8_t *)data;
 127     while (s->zstream.avail_in > 0) {
 128         ret = deflate(&s->zstream, Z_NO_FLUSH);
 129         if (ret != Z_OK)
 130             return -1;
 131         if (s->zstream.avail_out == 0) {
 132             if(s->bytestream_end - s->bytestream > IOBUF_SIZE + 100)
 133                 png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), s->buf, IOBUF_SIZE);
 134             s->zstream.avail_out = IOBUF_SIZE;
 135             s->zstream.next_out = s->buf;
 136         }
 137     }
 138     return 0;
 139 }
 140
 141 static int encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
 142     PNGEncContext *s = avctx->priv_data;
 143     AVFrame *pict = data;
 144     AVFrame * const p= (AVFrame*)&s->picture;
 145     int bit_depth, color_type, y, len, row_size, ret, is_progressive;
 146     int bits_per_pixel, pass_row_size;
 147     int compression_level;
 148     uint8_t *ptr;
 149     uint8_t *crow_buf = NULL;
 150     uint8_t *tmp_buf = NULL;
 151
 152     *p = *pict;
 153     p->pict_type= FF_I_TYPE;
 154     p->key_frame= 1;
 155
 156     s->bytestream_start=
 157     s->bytestream= buf;
 158     s->bytestream_end= buf+buf_size;
 159
 160     is_progressive = !!(avctx->flags & CODEC_FLAG_INTERLACED_DCT);
 161     switch(avctx->pix_fmt) {
 162     case PIX_FMT_RGB32:
 163         bit_depth = 8;
 164         color_type = PNG_COLOR_TYPE_RGB_ALPHA;
 165         break;
 166     case PIX_FMT_RGB24:
 167         bit_depth = 8;
 168         color_type = PNG_COLOR_TYPE_RGB;
 169         break;
 170     case PIX_FMT_GRAY8:
 171         bit_depth = 8;
 172         color_type = PNG_COLOR_TYPE_GRAY;
 173         break;
 174     case PIX_FMT_MONOBLACK:
 175         bit_depth = 1;
 176         color_type = PNG_COLOR_TYPE_GRAY;
 177         break;
 178     case PIX_FMT_PAL8:
 179         bit_depth = 8;
 180         color_type = PNG_COLOR_TYPE_PALETTE;
 181         break;
 182     default:
 183         return -1;
 184     }
 185     bits_per_pixel = ff_png_get_nb_channels(color_type) * bit_depth;
 186     row_size = (avctx->width * bits_per_pixel + 7) >> 3;
 187
 188     s->zstream.zalloc = ff_png_zalloc;
 189     s->zstream.zfree = ff_png_zfree;
 190     s->zstream.opaque = NULL;
 191     compression_level = avctx->compression_level == FF_COMPRESSION_DEFAULT ?
 192                             Z_DEFAULT_COMPRESSION :
 193                             av_clip(avctx->compression_level, 0, 9);
 194     ret = deflateInit2(&s->zstream, compression_level,
 195                        Z_DEFLATED, 15, 8, Z_DEFAULT_STRATEGY);
 196     if (ret != Z_OK)
 197         return -1;
 198     crow_buf = av_malloc(row_size + 1);
 199     if (!crow_buf)
 200         goto fail;
 201     if (is_progressive) {
 202         tmp_buf = av_malloc(row_size + 1);
 203         if (!tmp_buf)
 204             goto fail;
 205     }
 206
 207     /* write png header */
 208     memcpy(s->bytestream, ff_pngsig, 8);
 209     s->bytestream += 8;
 210
 211     AV_WB32(s->buf, avctx->width);
 212     AV_WB32(s->buf + 4, avctx->height);
 213     s->buf[8] = bit_depth;
 214     s->buf[9] = color_type;
 215     s->buf[10] = 0; /* compression type */
 216     s->buf[11] = 0; /* filter type */
 217     s->buf[12] = is_progressive; /* interlace type */
 218
 219     png_write_chunk(&s->bytestream, MKTAG('I', 'H', 'D', 'R'), s->buf, 13);
 220
 221     /* put the palette if needed */
 222     if (color_type == PNG_COLOR_TYPE_PALETTE) {
 223         int has_alpha, alpha, i;
 224         unsigned int v;
 225         uint32_t *palette;
 226         uint8_t *alpha_ptr;
 227
 228         palette = (uint32_t *)p->data[1];
 229         ptr = s->buf;
 230         alpha_ptr = s->buf + 256 * 3;
 231         has_alpha = 0;
 232         for(i = 0; i < 256; i++) {
 233             v = palette[i];
 234             alpha = v >> 24;
 235             if (alpha && alpha != 0xff)
 236                 has_alpha = 1;
 237             *alpha_ptr++ = alpha;
 238             bytestream_put_be24(&ptr, v);
 239         }
 240         png_write_chunk(&s->bytestream, MKTAG('P', 'L', 'T', 'E'), s->buf, 256 * 3);
 241         if (has_alpha) {
 242             png_write_chunk(&s->bytestream, MKTAG('t', 'R', 'N', 'S'), s->buf + 256 * 3, 256);
 243         }
 244     }
 245
 246     /* now put each row */
 247     s->zstream.avail_out = IOBUF_SIZE;
 248     s->zstream.next_out = s->buf;
 249     if (is_progressive) {
 250         uint8_t *ptr1;
 251         int pass;
 252
 253         for(pass = 0; pass < NB_PASSES; pass++) {
 254             /* NOTE: a pass is completely omited if no pixels would be
 255                output */
 256             pass_row_size = ff_png_pass_row_size(pass, bits_per_pixel, avctx->width);
 257             if (pass_row_size > 0) {
 258                 for(y = 0; y < avctx->height; y++) {
 259                     if ((ff_png_pass_ymask[pass] << (y & 7)) & 0x80) {
 260                         ptr = p->data[0] + y * p->linesize[0];
 261                         if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
 262                             convert_from_rgb32(tmp_buf, ptr, avctx->width);
 263                             ptr1 = tmp_buf;
 264                         } else {
 265                             ptr1 = ptr;
 266                         }
 267                         png_get_interlaced_row(crow_buf + 1, pass_row_size,
 268                                                bits_per_pixel, pass,
 269                                                ptr1, avctx->width);
 270                         crow_buf[0] = PNG_FILTER_VALUE_NONE;
 271                         png_write_row(s, crow_buf, pass_row_size + 1);
 272                     }
 273                 }
 274             }
 275         }
 276     } else {
 277         for(y = 0; y < avctx->height; y++) {
 278             ptr = p->data[0] + y * p->linesize[0];
 279             if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
 280                 convert_from_rgb32(crow_buf + 1, ptr, avctx->width);
 281             else
 282                 memcpy(crow_buf + 1, ptr, row_size);
 283             crow_buf[0] = PNG_FILTER_VALUE_NONE;
 284             png_write_row(s, crow_buf, row_size + 1);
 285         }
 286     }
 287     /* compress last bytes */
 288     for(;;) {
 289         ret = deflate(&s->zstream, Z_FINISH);
 290         if (ret == Z_OK || ret == Z_STREAM_END) {
 291             len = IOBUF_SIZE - s->zstream.avail_out;
 292             if (len > 0 && s->bytestream_end - s->bytestream > len + 100) {
 293                 png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), s->buf, len);
 294             }
 295             s->zstream.avail_out = IOBUF_SIZE;
 296             s->zstream.next_out = s->buf;
 297             if (ret == Z_STREAM_END)
 298                 break;
 299         } else {
 300             goto fail;
 301         }
 302     }
 303     png_write_chunk(&s->bytestream, MKTAG('I', 'E', 'N', 'D'), NULL, 0);
 304
 305     ret = s->bytestream - s->bytestream_start;
 306  the_end:
 307     av_free(crow_buf);
 308     av_free(tmp_buf);
 309     deflateEnd(&s->zstream);
 310     return ret;
 311  fail:
 312     ret = -1;
 313     goto the_end;
 314 }
 315
 316 static int png_enc_init(AVCodecContext *avctx){
 317     PNGEncContext *s = avctx->priv_data;
 318
 319     avcodec_get_frame_defaults((AVFrame*)&s->picture);
 320     avctx->coded_frame= (AVFrame*)&s->picture;
 321
 322     return 0;
 323 }
 324
 325 AVCodec png_encoder = {
 326     "png",
 327     CODEC_TYPE_VIDEO,
 328     CODEC_ID_PNG,
 329     sizeof(PNGEncContext),
 330     png_enc_init,
 331     encode_frame,
 332     NULL, //encode_end,
 333     .pix_fmts= (enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGB32, PIX_FMT_PAL8, PIX_FMT_GRAY8, PIX_FMT_MONOBLACK, -1},
 334 };