SGI image decoder ported to the new image API.

patch by Xiaohui Sun, sunxiaohui dsp.ac cn

Originally committed as revision 8635 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 156 insertions, 0 deletions

diff --git a/libavcodec/sgienc.c b/libavcodec/sgienc.c
new file mode 100644
index 0000000000..147bc8961c
--- /dev/null
+++ b/libavcodec/sgienc.c
@@ -0,0 +1,156 @@
+/*
+ * 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},
+};
+