libavcodec/sgienc.c

   1 /*
   2  * SGI image encoder
   3  * Todd Kirby <doubleshot@pacbell.net>
   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
  22 #include "avcodec.h"
  23 #include "bytestream.h"
  24 #include "sgi.h"
  25 #include "rle.h"
  26
  27 #define SGI_SINGLE_CHAN 2
  28 #define SGI_MULTI_CHAN 3
  29
  30 typedef struct SgiContext {
  31     AVFrame picture;
  32 } SgiContext;
  33
  34 static av_cold int encode_init(AVCodecContext *avctx)
  35 {
  36     SgiContext *s = avctx->priv_data;
  37
  38     avcodec_get_frame_defaults(&s->picture);
  39     avctx->coded_frame = &s->picture;
  40
  41     return 0;
  42 }
  43
  44 static int encode_frame(AVCodecContext *avctx, unsigned char *buf,
  45                         int buf_size, void *data)
  46 {
  47     SgiContext *s = avctx->priv_data;
  48     AVFrame * const p = &s->picture;
  49     uint8_t *offsettab, *lengthtab, *in_buf, *encode_buf;
  50     int x, y, z, length, tablesize;
  51     unsigned int width, height, depth, dimension;
  52     unsigned char *orig_buf = buf, *end_buf = buf + buf_size;
  53
  54     *p = *(AVFrame*)data;
  55     p->pict_type = FF_I_TYPE;
  56     p->key_frame = 1;
  57
  58     width  = avctx->width;
  59     height = avctx->height;
  60
  61     switch (avctx->pix_fmt) {
  62     case PIX_FMT_GRAY8:
  63         dimension = SGI_SINGLE_CHAN;
  64         depth     = SGI_GRAYSCALE;
  65         break;
  66     case PIX_FMT_RGB24:
  67         dimension = SGI_MULTI_CHAN;
  68         depth     = SGI_RGB;
  69         break;
  70     case PIX_FMT_RGBA:
  71         dimension = SGI_MULTI_CHAN;
  72         depth     = SGI_RGBA;
  73         break;
  74     default:
  75         return AVERROR_INVALIDDATA;
  76     }
  77
  78     tablesize = depth * height * 4;
  79     length = tablesize * 2 + SGI_HEADER_SIZE;
  80
  81     if (buf_size < length) {
  82         av_log(avctx, AV_LOG_ERROR, "buf_size too small(need %d, got %d)\n", length, buf_size);
  83         return -1;
  84     }
  85
  86     /* Encode header. */
  87     bytestream_put_be16(&buf, SGI_MAGIC);
  88     bytestream_put_byte(&buf, avctx->coder_type != FF_CODER_TYPE_RAW); /* RLE 1 - VERBATIM 0*/
  89     bytestream_put_byte(&buf, 1); /* bytes_per_channel */
  90     bytestream_put_be16(&buf, dimension);
  91     bytestream_put_be16(&buf, width);
  92     bytestream_put_be16(&buf, height);
  93     bytestream_put_be16(&buf, depth);
  94
  95     /* The rest are constant in this implementation. */
  96     bytestream_put_be32(&buf, 0L); /* pixmin */
  97     bytestream_put_be32(&buf, 255L); /* pixmax */
  98     bytestream_put_be32(&buf, 0L); /* dummy */
  99
 100     /* name */
 101     memset(buf, 0, SGI_HEADER_SIZE);
 102     buf += 80;
 103
 104      /* colormap */
 105     bytestream_put_be32(&buf, 0L);
 106
 107     /* The rest of the 512 byte header is unused. */
 108     buf += 404;
 109     offsettab = buf;
 110
 111     if (avctx->coder_type  != FF_CODER_TYPE_RAW) {
 112         /* Skip RLE offset table. */
 113         buf += tablesize;
 114         lengthtab = buf;
 115
 116         /* Skip RLE length table. */
 117         buf += tablesize;
 118
 119         /* Make an intermediate consecutive buffer. */
 120         if (!(encode_buf = av_malloc(width)))
 121             return -1;
 122
 123         for (z = 0; z < depth; z++) {
 124             in_buf = p->data[0] + p->linesize[0] * (height - 1) + z;
 125
 126             for (y = 0; y < height; y++) {
 127                 bytestream_put_be32(&offsettab, buf - orig_buf);
 128
 129                 for (x = 0; x < width; x++)
 130                     encode_buf[x] = in_buf[depth * x];
 131
 132                 if ((length = ff_rle_encode(buf, end_buf - buf - 1, encode_buf, 1, width, 0, 0, 0x80, 0)) < 1) {
 133                     av_free(encode_buf);
 134                     return -1;
 135                 }
 136
 137                 buf += length;
 138                 bytestream_put_byte(&buf, 0);
 139                 bytestream_put_be32(&lengthtab, length + 1);
 140                 in_buf -= p->linesize[0];
 141             }
 142         }
 143
 144         av_free(encode_buf);
 145     } else {
 146         for (z = 0; z < depth; z++) {
 147             in_buf = p->data[0] + p->linesize[0] * (height - 1) + z;
 148
 149             for (y = 0; y < height; y++) {
 150                 for (x = 0; x < width * depth; x += depth)
 151                     bytestream_put_byte(&buf, in_buf[x]);
 152
 153                 in_buf -= p->linesize[0];
 154             }
 155         }
 156     }
 157
 158     /* total length */
 159     return buf - orig_buf;
 160 }
 161
 162 AVCodec sgi_encoder = {
 163     "sgi",
 164     CODEC_TYPE_VIDEO,
 165     CODEC_ID_SGI,
 166     sizeof(SgiContext),
 167     encode_init,
 168     encode_frame,
 169     NULL,
 170     .pix_fmts= (const enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGBA, PIX_FMT_GRAY8, PIX_FMT_NONE},
 171     .long_name= NULL_IF_CONFIG_SMALL("SGI image"),
 172 };