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libavcodec/sgienc.c

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00001 /*
00002  * SGI image encoder
00003  * Todd Kirby <doubleshot@pacbell.net>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "avcodec.h"
00023 #include "bytestream.h"
00024 #include "sgi.h"
00025 #include "rle.h"
00026 
00027 #define SGI_SINGLE_CHAN 2
00028 #define SGI_MULTI_CHAN 3
00029 
00030 typedef struct SgiContext {
00031     AVFrame picture;
00032 } SgiContext;
00033 
00034 static av_cold int encode_init(AVCodecContext *avctx){
00035     SgiContext *s = avctx->priv_data;
00036 
00037     avcodec_get_frame_defaults(&s->picture);
00038     avctx->coded_frame = &s->picture;
00039 
00040     return 0;
00041 }
00042 
00043 static int encode_frame(AVCodecContext *avctx, unsigned char *buf,
00044                         int buf_size, void *data) {
00045     SgiContext *s = avctx->priv_data;
00046     AVFrame * const p = &s->picture;
00047     uint8_t *offsettab, *lengthtab, *in_buf, *encode_buf;
00048     int x, y, z, length, tablesize;
00049     unsigned int width, height, depth, dimension;
00050     unsigned char *orig_buf = buf, *end_buf = buf + buf_size;
00051 
00052     *p = *(AVFrame*)data;
00053     p->pict_type = FF_I_TYPE;
00054     p->key_frame = 1;
00055 
00056     width = avctx->width;
00057     height = avctx->height;
00058 
00059     switch (avctx->pix_fmt) {
00060         case PIX_FMT_GRAY8:
00061             dimension = SGI_SINGLE_CHAN;
00062             depth = SGI_GRAYSCALE;
00063             break;
00064         case PIX_FMT_RGB24:
00065             dimension = SGI_MULTI_CHAN;
00066             depth = SGI_RGB;
00067             break;
00068         case PIX_FMT_RGBA:
00069             dimension = SGI_MULTI_CHAN;
00070             depth = SGI_RGBA;
00071             break;
00072         default:
00073             return AVERROR_INVALIDDATA;
00074     }
00075 
00076     tablesize = depth * height * 4;
00077     length = tablesize * 2 + SGI_HEADER_SIZE;
00078 
00079     if (buf_size < length) {
00080         av_log(avctx, AV_LOG_ERROR, "buf_size too small(need %d, got %d)\n", length, buf_size);
00081         return -1;
00082     }
00083 
00084     /* Encode header. */
00085     bytestream_put_be16(&buf, SGI_MAGIC);
00086     bytestream_put_byte(&buf, 1); /* RLE */
00087     bytestream_put_byte(&buf, 1); /* bytes_per_channel */
00088     bytestream_put_be16(&buf, dimension);
00089     bytestream_put_be16(&buf, width);
00090     bytestream_put_be16(&buf, height);
00091     bytestream_put_be16(&buf, depth);
00092 
00093     /* The rest are constant in this implementation. */
00094     bytestream_put_be32(&buf, 0L); /* pixmin */
00095     bytestream_put_be32(&buf, 255L); /* pixmax */
00096     bytestream_put_be32(&buf, 0L); /* dummy */
00097 
00098     /* name */
00099     memset(buf, 0, SGI_HEADER_SIZE);
00100     buf += 80;
00101 
00102      /* colormap */
00103     bytestream_put_be32(&buf, 0L);
00104 
00105     /* The rest of the 512 byte header is unused. */
00106     buf += 404;
00107     offsettab = buf;
00108 
00109     /* Skip RLE offset table. */
00110     buf += tablesize;
00111     lengthtab = buf;
00112 
00113     /* Skip RLE length table. */
00114     buf += tablesize;
00115 
00116     /* Make an intermediate consecutive buffer. */
00117     if ((encode_buf = av_malloc(width)) == NULL)
00118         return -1;
00119 
00120     for (z = 0; z < depth; z++) {
00121         in_buf = p->data[0] + p->linesize[0] * (height - 1) + z;
00122 
00123         for (y = 0; y < height; y++) {
00124             bytestream_put_be32(&offsettab, buf - orig_buf);
00125 
00126             for (x = 0; x < width; x++)
00127                 encode_buf[x] = in_buf[depth * x];
00128 
00129             if((length = ff_rle_encode(buf, end_buf - buf - 1, encode_buf, 1, width, 0, 0, 0x80, 0)) < 1) {
00130                 av_free(encode_buf);
00131                 return -1;
00132             }
00133 
00134             buf += length;
00135             bytestream_put_byte(&buf, 0);
00136             bytestream_put_be32(&lengthtab, length + 1);
00137             in_buf -= p->linesize[0];
00138         }
00139     }
00140 
00141     av_free(encode_buf);
00142     /* total length */
00143     return buf - orig_buf;
00144 }
00145 
00146 AVCodec sgi_encoder = {
00147     "sgi",
00148     CODEC_TYPE_VIDEO,
00149     CODEC_ID_SGI,
00150     sizeof(SgiContext),
00151     encode_init,
00152     encode_frame,
00153     NULL,
00154     .pix_fmts= (enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGBA, PIX_FMT_PAL8, PIX_FMT_GRAY8, PIX_FMT_NONE},
00155     .long_name= NULL_IF_CONFIG_SMALL("SGI image"),
00156 };
00157 

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