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, 267 insertions, 0 deletions

diff --git a/libavcodec/sgidec.c b/libavcodec/sgidec.c
new file mode 100644
index 0000000000..aac32b4166
--- /dev/null
+++ b/libavcodec/sgidec.c
@@ -0,0 +1,267 @@
+/*
+ * SGI image decoder
+ * 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"
+
+typedef struct SgiState {
+    AVFrame picture;
+    unsigned int width;
+    unsigned int height;
+    unsigned int depth;
+    int linesize;
+} SgiState;
+
+/**
+ * Expand an RLE row into a channel.
+ * @param in_buf input buffer
+ * @param in_end end of input buffer
+ * @param out_buf Points to one line after the output buffer.
+ * @param out_end end of line in output buffer
+ * @param pixelstride pixel stride of input buffer
+ * @return size of output in bytes, -1 if buffer overflows
+ */
+static int expand_rle_row(uint8_t *in_buf, uint8_t* in_end,
+            unsigned char *out_buf, uint8_t* out_end, int pixelstride)
+{
+    unsigned char pixel, count;
+    unsigned char *orig = out_buf;
+
+    while (1) {
+        if(in_buf + 1 > in_end) return -1;
+        pixel = bytestream_get_byte(&in_buf);
+        if (!(count = (pixel & 0x7f))) {
+            return (out_buf - orig) / pixelstride;
+        }
+
+        /* Check for buffer overflow. */
+        if(out_buf + pixelstride * count >= out_end) return -1;
+
+        if (pixel & 0x80) {
+            while (count--) {
+                *out_buf = bytestream_get_byte(&in_buf);
+                out_buf += pixelstride;
+            }
+        } else {
+            pixel = bytestream_get_byte(&in_buf);
+
+            while (count--) {
+                *out_buf = pixel;
+                out_buf += pixelstride;
+            }
+        }
+    }
+}
+
+/**
+ * Read a run length encoded SGI image.
+ * @param out_buf output buffer
+ * @param in_buf input buffer
+ * @param in_end end of input buffer
+ * @param s the current image state
+ * @return 0 if no error, else return error number.
+ */
+static int read_rle_sgi(unsigned char* out_buf, uint8_t *in_buf,
+                        uint8_t *in_end, SgiState* s)
+{
+    uint8_t *dest_row;
+    unsigned int len = s->height * s->depth * 4;
+    uint8_t *start_table = in_buf;
+    unsigned int y, z;
+    unsigned int start_offset;
+
+    /* size of  RLE offset and length tables */
+    if(len * 2  > in_end - in_buf) {
+        return AVERROR_INVALIDDATA;
+    }
+
+    in_buf -= SGI_HEADER_SIZE;
+    for (z = 0; z < s->depth; z++) {
+        dest_row = out_buf;
+        for (y = 0; y < s->height; y++) {
+            dest_row -= s->linesize;
+            start_offset = bytestream_get_be32(&start_table);
+            if(start_offset > in_end - in_buf) {
+                return AVERROR_INVALIDDATA;
+            }
+            if (expand_rle_row(in_buf + start_offset, in_end, dest_row + z,
+                dest_row + FFABS(s->linesize), s->depth) != s->width)
+                return AVERROR_INVALIDDATA;
+        }
+    }
+    return 0;
+}
+
+/**
+ * Read an uncompressed SGI image.
+ * @param out_buf output buffer
+ * @param out_end end ofoutput buffer
+ * @param in_buf input buffer
+ * @param in_end end of input buffer
+ * @param s the current image state
+ * @return 0 if read success, otherwise return -1.
+ */
+static int read_uncompressed_sgi(unsigned char* out_buf, uint8_t* out_end,
+                uint8_t *in_buf, uint8_t *in_end, SgiState* s)
+{
+    int x, y, z;
+    uint8_t *ptr;
+    unsigned int offset = s->height * s->width;
+
+    /* Test buffer size. */
+    if (offset * s->depth > in_end - in_buf) {
+       return -1;
+    }
+
+    for (y = s->height - 1; y >= 0; y--) {
+        out_end = out_buf + (y * s->linesize);
+        for (x = s->width; x > 0; x--) {
+            ptr = in_buf++;
+            for(z = 0; z < s->depth; z ++) {
+                bytestream_put_byte(&out_end, *ptr);
+                ptr += offset;
+            }
+        }
+    }
+    return 0;
+}
+
+static int decode_frame(AVCodecContext *avctx,
+                        void *data, int *data_size,
+                        uint8_t *in_buf, int buf_size)
+{
+    SgiState *s = avctx->priv_data;
+    AVFrame *picture = data;
+    AVFrame *p = &s->picture;
+    uint8_t *in_end = in_buf + buf_size;
+    unsigned int dimension, bytes_per_channel, rle;
+    int ret = 0;
+    uint8_t *out_buf, *out_end;
+
+    if (buf_size < SGI_HEADER_SIZE){
+        av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", buf_size);
+        return -1;
+    }
+
+    /* Test for SGI magic. */
+    if (bytestream_get_be16(&in_buf) != SGI_MAGIC) {
+        av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
+        return -1;
+    }
+
+    rle = bytestream_get_byte(&in_buf);
+    bytes_per_channel = bytestream_get_byte(&in_buf);
+    dimension = bytestream_get_be16(&in_buf);
+    s->width  = bytestream_get_be16(&in_buf);
+    s->height = bytestream_get_be16(&in_buf);
+    s->depth  = bytestream_get_be16(&in_buf);
+
+    if (bytes_per_channel != 1) {
+        av_log(avctx, AV_LOG_ERROR, "wrong channel number\n");
+        return -1;
+    }
+
+    /* Check for supported image dimensions. */
+    if (dimension != 2 && dimension != 3) {
+        av_log(avctx, AV_LOG_ERROR, "wrong dimension number\n");
+        return -1;
+    }
+
+    if (s->depth == SGI_GRAYSCALE) {
+        avctx->pix_fmt = PIX_FMT_GRAY8;
+    } else if (s->depth == SGI_RGB) {
+        avctx->pix_fmt = PIX_FMT_RGB24;
+    } else if (s->depth == SGI_RGBA) {
+        avctx->pix_fmt = PIX_FMT_RGBA;
+    } else {
+        av_log(avctx, AV_LOG_ERROR, "wrong picture format\n");
+        return -1;
+    }
+
+    if (avcodec_check_dimensions(avctx, s->width, s->height))
+        return -1;
+    avcodec_set_dimensions(avctx, s->width, s->height);
+
+    if (p->data[0])
+        avctx->release_buffer(avctx, p);
+
+    p->reference = 0;
+    if (avctx->get_buffer(avctx, p) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed.\n");
+        return -1;
+    }
+
+    p->pict_type = FF_I_TYPE;
+    p->key_frame = 1;
+    out_buf = p->data[0];
+
+    out_end = out_buf + p->linesize[0] * s->height;
+
+    s->linesize = p->linesize[0];
+
+    /* Skip header. */
+    in_buf += SGI_HEADER_SIZE - 12;
+    if (rle) {
+        ret = read_rle_sgi(out_end, in_buf, in_end, s);
+    } else {
+        ret = read_uncompressed_sgi(out_buf, out_end, in_buf, in_end, s);
+    }
+
+    if (ret == 0) {
+        *picture   = s->picture;
+        *data_size = sizeof(AVPicture);
+        return buf_size;
+    } else {
+        return -1;
+    }
+}
+
+static int sgi_init(AVCodecContext *avctx){
+    SgiState *s = avctx->priv_data;
+
+    avcodec_get_frame_defaults(&s->picture);
+    avctx->coded_frame = &s->picture;
+
+    return 0;
+}
+
+static int sgi_end(AVCodecContext *avctx)
+{
+    SgiState * const s = avctx->priv_data;
+
+    if (s->picture.data[0])
+        avctx->release_buffer(avctx, &s->picture);
+
+    return 0;
+}
+
+AVCodec sgi_decoder = {
+    "sgi",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_SGI,
+    sizeof(SgiState),
+    sgi_init,
+    NULL,
+    sgi_end,
+    decode_frame,
+};
+