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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 {
00036     SgiContext *s = avctx->priv_data;
00037 
00038     avcodec_get_frame_defaults(&s->picture);
00039     avctx->coded_frame = &s->picture;
00040 
00041     return 0;
00042 }
00043 
00044 static int encode_frame(AVCodecContext *avctx, unsigned char *buf,
00045                         int buf_size, void *data)
00046 {
00047     SgiContext *s = avctx->priv_data;
00048     AVFrame * const p = &s->picture;
00049     uint8_t *offsettab, *lengthtab, *in_buf, *encode_buf;
00050     int x, y, z, length, tablesize;
00051     unsigned int width, height, depth, dimension;
00052     unsigned char *orig_buf = buf, *end_buf = buf + buf_size;
00053 
00054     *p = *(AVFrame*)data;
00055     p->pict_type = FF_I_TYPE;
00056     p->key_frame = 1;
00057 
00058     width  = avctx->width;
00059     height = avctx->height;
00060 
00061     switch (avctx->pix_fmt) {
00062     case PIX_FMT_GRAY8:
00063         dimension = SGI_SINGLE_CHAN;
00064         depth     = SGI_GRAYSCALE;
00065         break;
00066     case PIX_FMT_RGB24:
00067         dimension = SGI_MULTI_CHAN;
00068         depth     = SGI_RGB;
00069         break;
00070     case PIX_FMT_RGBA:
00071         dimension = SGI_MULTI_CHAN;
00072         depth     = SGI_RGBA;
00073         break;
00074     default:
00075         return AVERROR_INVALIDDATA;
00076     }
00077 
00078     tablesize = depth * height * 4;
00079     length = tablesize * 2 + SGI_HEADER_SIZE;
00080 
00081     if (buf_size < length) {
00082         av_log(avctx, AV_LOG_ERROR, "buf_size too small(need %d, got %d)\n", length, buf_size);
00083         return -1;
00084     }
00085 
00086     /* Encode header. */
00087     bytestream_put_be16(&buf, SGI_MAGIC);
00088     bytestream_put_byte(&buf, avctx->coder_type != FF_CODER_TYPE_RAW); /* RLE 1 - VERBATIM 0*/
00089     bytestream_put_byte(&buf, 1); /* bytes_per_channel */
00090     bytestream_put_be16(&buf, dimension);
00091     bytestream_put_be16(&buf, width);
00092     bytestream_put_be16(&buf, height);
00093     bytestream_put_be16(&buf, depth);
00094 
00095     /* The rest are constant in this implementation. */
00096     bytestream_put_be32(&buf, 0L); /* pixmin */
00097     bytestream_put_be32(&buf, 255L); /* pixmax */
00098     bytestream_put_be32(&buf, 0L); /* dummy */
00099 
00100     /* name */
00101     memset(buf, 0, SGI_HEADER_SIZE);
00102     buf += 80;
00103 
00104      /* colormap */
00105     bytestream_put_be32(&buf, 0L);
00106 
00107     /* The rest of the 512 byte header is unused. */
00108     buf += 404;
00109     offsettab = buf;
00110 
00111     if (avctx->coder_type  != FF_CODER_TYPE_RAW) {
00112         /* Skip RLE offset table. */
00113         buf += tablesize;
00114         lengthtab = buf;
00115 
00116         /* Skip RLE length table. */
00117         buf += tablesize;
00118 
00119         /* Make an intermediate consecutive buffer. */
00120         if (!(encode_buf = av_malloc(width)))
00121             return -1;
00122 
00123         for (z = 0; z < depth; z++) {
00124             in_buf = p->data[0] + p->linesize[0] * (height - 1) + z;
00125 
00126             for (y = 0; y < height; y++) {
00127                 bytestream_put_be32(&offsettab, buf - orig_buf);
00128 
00129                 for (x = 0; x < width; x++)
00130                     encode_buf[x] = in_buf[depth * x];
00131 
00132                 if ((length = ff_rle_encode(buf, end_buf - buf - 1, encode_buf, 1, width, 0, 0, 0x80, 0)) < 1) {
00133                     av_free(encode_buf);
00134                     return -1;
00135                 }
00136 
00137                 buf += length;
00138                 bytestream_put_byte(&buf, 0);
00139                 bytestream_put_be32(&lengthtab, length + 1);
00140                 in_buf -= p->linesize[0];
00141             }
00142         }
00143 
00144         av_free(encode_buf);
00145     } else {
00146         for (z = 0; z < depth; z++) {
00147             in_buf = p->data[0] + p->linesize[0] * (height - 1) + z;
00148 
00149             for (y = 0; y < height; y++) {
00150                 for (x = 0; x < width * depth; x += depth)
00151                     bytestream_put_byte(&buf, in_buf[x]);
00152 
00153                 in_buf -= p->linesize[0];
00154             }
00155         }
00156     }
00157 
00158     /* total length */
00159     return buf - orig_buf;
00160 }
00161 
00162 AVCodec sgi_encoder = {
00163     "sgi",
00164     AVMEDIA_TYPE_VIDEO,
00165     CODEC_ID_SGI,
00166     sizeof(SgiContext),
00167     encode_init,
00168     encode_frame,
00169     NULL,
00170     .pix_fmts= (const enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGBA, PIX_FMT_GRAY8, PIX_FMT_NONE},
00171     .long_name= NULL_IF_CONFIG_SMALL("SGI image"),
00172 };

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