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     SgiContext *s = avctx->priv_data;
  36
  37     avcodec_get_frame_defaults(&s->picture);
  38     avctx->coded_frame = &s->picture;
  39
  40     return 0;
  41 }
  42
  43 static int encode_frame(AVCodecContext *avctx, unsigned char *buf,
  44                         int buf_size, void *data) {
  45     SgiContext *s = avctx->priv_data;
  46     AVFrame * const p = &s->picture;
  47     uint8_t *offsettab, *lengthtab, *in_buf, *encode_buf;
  48     int x, y, z, length, tablesize;
  49     unsigned int width, height, depth, dimension;
  50     unsigned char *orig_buf = buf, *end_buf = buf + buf_size;
  51
  52     *p = *(AVFrame*)data;
  53     p->pict_type = FF_I_TYPE;
  54     p->key_frame = 1;
  55
  56     width = avctx->width;
  57     height = avctx->height;
  58
  59     switch (avctx->pix_fmt) {
  60         case PIX_FMT_GRAY8:
  61             dimension = SGI_SINGLE_CHAN;
  62             depth = SGI_GRAYSCALE;
  63             break;
  64         case PIX_FMT_RGB24:
  65             dimension = SGI_MULTI_CHAN;
  66             depth = SGI_RGB;
  67             break;
  68         case PIX_FMT_RGBA:
  69             dimension = SGI_MULTI_CHAN;
  70             depth = SGI_RGBA;
  71             break;
  72         default:
  73             return AVERROR_INVALIDDATA;
  74     }
  75
  76     tablesize = depth * height * 4;
  77     length = tablesize * 2 + SGI_HEADER_SIZE;
  78
  79     if (buf_size < length) {
  80         av_log(avctx, AV_LOG_ERROR, "buf_size too small(need %d, got %d)\n", length, buf_size);
  81         return -1;
  82     }
  83
  84     /* Encode header. */
  85     bytestream_put_be16(&buf, SGI_MAGIC);
  86     bytestream_put_byte(&buf, 1); /* RLE */
  87     bytestream_put_byte(&buf, 1); /* bytes_per_channel */
  88     bytestream_put_be16(&buf, dimension);
  89     bytestream_put_be16(&buf, width);
  90     bytestream_put_be16(&buf, height);
  91     bytestream_put_be16(&buf, depth);
  92
  93     /* The rest are constant in this implementation. */
  94     bytestream_put_be32(&buf, 0L); /* pixmin */
  95     bytestream_put_be32(&buf, 255L); /* pixmax */
  96     bytestream_put_be32(&buf, 0L); /* dummy */
  97
  98     /* name */
  99     memset(buf, 0, SGI_HEADER_SIZE);
 100     buf += 80;
 101
 102      /* colormap */
 103     bytestream_put_be32(&buf, 0L);
 104
 105     /* The rest of the 512 byte header is unused. */
 106     buf += 404;
 107     offsettab = buf;
 108
 109     /* Skip RLE offset table. */
 110     buf += tablesize;
 111     lengthtab = buf;
 112
 113     /* Skip RLE length table. */
 114     buf += tablesize;
 115
 116     /* Make an intermediate consecutive buffer. */
 117     if ((encode_buf = av_malloc(width)) == NULL)
 118         return -1;
 119
 120     for (z = 0; z < depth; z++) {
 121         in_buf = p->data[0] + p->linesize[0] * (height - 1) + z;
 122
 123         for (y = 0; y < height; y++) {
 124             bytestream_put_be32(&offsettab, buf - orig_buf);
 125
 126             for (x = 0; x < width; x++)
 127                 encode_buf[x] = in_buf[depth * x];
 128
 129             if((length = ff_rle_encode(buf, end_buf - buf - 1, encode_buf, 1, width, 0, 0, 0x80, 0)) < 1) {
 130                 av_free(encode_buf);
 131                 return -1;
 132             }
 133
 134             buf += length;
 135             bytestream_put_byte(&buf, 0);
 136             bytestream_put_be32(&lengthtab, length + 1);
 137             in_buf -= p->linesize[0];
 138         }
 139     }
 140
 141     av_free(encode_buf);
 142     /* total length */
 143     return buf - orig_buf;
 144 }
 145
 146 AVCodec sgi_encoder = {
 147     "sgi",
 148     CODEC_TYPE_VIDEO,
 149     CODEC_ID_SGI,
 150     sizeof(SgiContext),
 151     encode_init,
 152     encode_frame,
 153     NULL,
 154     .pix_fmts= (enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGBA, PIX_FMT_PAL8, PIX_FMT_GRAY8, PIX_FMT_NONE},
 155     .long_name= NULL_IF_CONFIG_SMALL("SGI image"),
 156 };
 157