ffmpeg/libavcodec/sgienc.c

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/*
* SGI image encoder
* Todd Kirby <doubleshot@pacbell.net>
*
* 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
*/
#include "avcodec.h"
#include "bytestream.h"
#include "sgi.h"
#include "rle.h"
#define SGI_SINGLE_CHAN 2
#define SGI_MULTI_CHAN 3
typedef struct SgiContext {
AVFrame picture;
} SgiContext;
static int encode_init(AVCodecContext *avctx){
SgiContext *s = avctx->priv_data;
avcodec_get_frame_defaults(&s->picture);
avctx->coded_frame = &s->picture;
return 0;
}
static int encode_frame(AVCodecContext *avctx, unsigned char *buf,
int buf_size, void *data) {
SgiContext *s = avctx->priv_data;
AVFrame * const p = &s->picture;
uint8_t *offsettab, *lengthtab, *in_buf, *encode_buf;
int x, y, z, length, tablesize;
unsigned int width, height, depth, dimension;
unsigned char *orig_buf = buf, *end_buf = buf + buf_size;
*p = *(AVFrame*)data;
p->pict_type = FF_I_TYPE;
p->key_frame = 1;
width = avctx->width;
height = avctx->height;
switch (avctx->pix_fmt) {
case PIX_FMT_GRAY8:
dimension = SGI_SINGLE_CHAN;
depth = SGI_GRAYSCALE;
break;
case PIX_FMT_RGB24:
dimension = SGI_MULTI_CHAN;
depth = SGI_RGB;
break;
case PIX_FMT_RGBA:
dimension = SGI_MULTI_CHAN;
depth = SGI_RGBA;
break;
default:
return AVERROR_INVALIDDATA;
}
tablesize = depth * height * 4;
length = tablesize * 2 + SGI_HEADER_SIZE;
if (buf_size < length) {
av_log(avctx, AV_LOG_ERROR, "buf_size too small(need %d, got %d)\n", length, buf_size);
return -1;
}
/* Encode header. */
bytestream_put_be16(&buf, SGI_MAGIC);
bytestream_put_byte(&buf, 1); /* RLE */
bytestream_put_byte(&buf, 1); /* bytes_per_channel */
bytestream_put_be16(&buf, dimension);
bytestream_put_be16(&buf, width);
bytestream_put_be16(&buf, height);
bytestream_put_be16(&buf, depth);
/* The rest are constant in this implementation. */
bytestream_put_be32(&buf, 0L); /* pixmin */
bytestream_put_be32(&buf, 255L); /* pixmax */
bytestream_put_be32(&buf, 0L); /* dummy */
/* name */
memset(buf, 0, SGI_HEADER_SIZE);
buf += 80;
/* colormap */
bytestream_put_be32(&buf, 0L);
/* The rest of the 512 byte header is unused. */
buf += 404;
offsettab = buf;
/* Skip RLE offset table. */
buf += tablesize;
lengthtab = buf;
/* Skip RLE length table. */
buf += tablesize;
/* Make an intermediate consecutive buffer. */
if ((encode_buf = av_malloc(width)) == NULL)
return -1;
for (z = 0; z < depth; z++) {
in_buf = p->data[0] + p->linesize[0] * (height - 1) + z;
for (y = 0; y < height; y++) {
bytestream_put_be32(&offsettab, buf - orig_buf);
for (x = 0; x < width; x++)
encode_buf[x] = in_buf[depth * x];
if((length = ff_rle_encode(buf, end_buf - buf - 1, encode_buf, 1, width, 0, 0, 0x80, 0)) < 1) {
av_free(encode_buf);
return -1;
}
buf += length;
bytestream_put_byte(&buf, 0);
bytestream_put_be32(&lengthtab, length + 1);
in_buf -= p->linesize[0];
}
}
av_free(encode_buf);
/* total length */
return buf - orig_buf;
}
AVCodec sgi_encoder = {
"sgi",
CODEC_TYPE_VIDEO,
CODEC_ID_SGI,
sizeof(SgiContext),
encode_init,
encode_frame,
NULL,
.pix_fmts= (enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGBA, PIX_FMT_PAL8, PIX_FMT_GRAY8, -1},
};