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Diffstat (limited to 'ffmpeg/libavcodec/sgidec.c')
-rw-r--r--ffmpeg/libavcodec/sgidec.c243
1 files changed, 243 insertions, 0 deletions
diff --git a/ffmpeg/libavcodec/sgidec.c b/ffmpeg/libavcodec/sgidec.c
new file mode 100644
index 0000000..e7f453b
--- /dev/null
+++ b/ffmpeg/libavcodec/sgidec.c
@@ -0,0 +1,243 @@
+/*
+ * 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 "libavutil/imgutils.h"
+#include "libavutil/avassert.h"
+#include "avcodec.h"
+#include "bytestream.h"
+#include "internal.h"
+#include "sgi.h"
+
+typedef struct SgiState {
+ unsigned int width;
+ unsigned int height;
+ unsigned int depth;
+ unsigned int bytes_per_channel;
+ int linesize;
+ GetByteContext g;
+} SgiState;
+
+/**
+ * Expand an RLE row into a channel.
+ * @param s the current image state
+ * @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(SgiState *s, uint8_t *out_buf,
+ uint8_t *out_end, int pixelstride)
+{
+ unsigned char pixel, count;
+ unsigned char *orig = out_buf;
+
+ while (out_buf < out_end) {
+ if (bytestream2_get_bytes_left(&s->g) < 1)
+ return AVERROR_INVALIDDATA;
+ pixel = bytestream2_get_byteu(&s->g);
+ if (!(count = (pixel & 0x7f))) {
+ break;
+ }
+
+ /* Check for buffer overflow. */
+ if(out_buf + pixelstride * (count-1) >= out_end) return -1;
+
+ if (pixel & 0x80) {
+ while (count--) {
+ *out_buf = bytestream2_get_byte(&s->g);
+ out_buf += pixelstride;
+ }
+ } else {
+ pixel = bytestream2_get_byte(&s->g);
+
+ while (count--) {
+ *out_buf = pixel;
+ out_buf += pixelstride;
+ }
+ }
+ }
+ return (out_buf - orig) / pixelstride;
+}
+
+/**
+ * Read a run length encoded SGI image.
+ * @param out_buf output buffer
+ * @param s the current image state
+ * @return 0 if no error, else return error number.
+ */
+static int read_rle_sgi(uint8_t *out_buf, SgiState *s)
+{
+ uint8_t *dest_row;
+ unsigned int len = s->height * s->depth * 4;
+ GetByteContext g_table = s->g;
+ unsigned int y, z;
+ unsigned int start_offset;
+
+ /* size of RLE offset and length tables */
+ if (len * 2 > bytestream2_get_bytes_left(&s->g)) {
+ return AVERROR_INVALIDDATA;
+ }
+
+ for (z = 0; z < s->depth; z++) {
+ dest_row = out_buf;
+ for (y = 0; y < s->height; y++) {
+ dest_row -= s->linesize;
+ start_offset = bytestream2_get_be32(&g_table);
+ bytestream2_seek(&s->g, start_offset, SEEK_SET);
+ if (expand_rle_row(s, dest_row + z, dest_row + s->width*s->depth,
+ s->depth) != s->width) {
+ return AVERROR_INVALIDDATA;
+ }
+ }
+ }
+ return 0;
+}
+
+/**
+ * Read an uncompressed SGI image.
+ * @param out_buf output buffer
+ * @param s the current image state
+ * @return 0 if read success, otherwise return -1.
+ */
+static int read_uncompressed_sgi(unsigned char* out_buf, SgiState *s)
+{
+ int x, y, z;
+ unsigned int offset = s->height * s->width * s->bytes_per_channel;
+ GetByteContext gp[4];
+ uint8_t *out_end;
+
+ /* Test buffer size. */
+ if (offset * s->depth > bytestream2_get_bytes_left(&s->g))
+ return AVERROR_INVALIDDATA;
+
+ /* Create a reader for each plane */
+ for (z = 0; z < s->depth; z++) {
+ gp[z] = s->g;
+ bytestream2_skip(&gp[z], z * offset);
+ }
+
+ for (y = s->height - 1; y >= 0; y--) {
+ out_end = out_buf + (y * s->linesize);
+ if (s->bytes_per_channel == 1) {
+ for (x = s->width; x > 0; x--)
+ for (z = 0; z < s->depth; z++)
+ *out_end++ = bytestream2_get_byteu(&gp[z]);
+ } else {
+ uint16_t *out16 = (uint16_t *)out_end;
+ for (x = s->width; x > 0; x--)
+ for (z = 0; z < s->depth; z++)
+ *out16++ = bytestream2_get_ne16u(&gp[z]);
+ }
+ }
+ return 0;
+}
+
+static int decode_frame(AVCodecContext *avctx,
+ void *data, int *got_frame,
+ AVPacket *avpkt)
+{
+ SgiState *s = avctx->priv_data;
+ AVFrame *p = data;
+ unsigned int dimension, rle;
+ int ret = 0;
+ uint8_t *out_buf, *out_end;
+
+ bytestream2_init(&s->g, avpkt->data, avpkt->size);
+ if (bytestream2_get_bytes_left(&s->g) < SGI_HEADER_SIZE) {
+ av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", avpkt->size);
+ return AVERROR_INVALIDDATA;
+ }
+
+ /* Test for SGI magic. */
+ if (bytestream2_get_be16u(&s->g) != SGI_MAGIC) {
+ av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ rle = bytestream2_get_byteu(&s->g);
+ s->bytes_per_channel = bytestream2_get_byteu(&s->g);
+ dimension = bytestream2_get_be16u(&s->g);
+ s->width = bytestream2_get_be16u(&s->g);
+ s->height = bytestream2_get_be16u(&s->g);
+ s->depth = bytestream2_get_be16u(&s->g);
+
+ if (s->bytes_per_channel != 1 && (s->bytes_per_channel != 2 || rle)) {
+ 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 = s->bytes_per_channel == 2 ? AV_PIX_FMT_GRAY16BE : AV_PIX_FMT_GRAY8;
+ } else if (s->depth == SGI_RGB) {
+ avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGB48BE : AV_PIX_FMT_RGB24;
+ } else if (s->depth == SGI_RGBA) {
+ avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGBA64BE : AV_PIX_FMT_RGBA;
+ } else {
+ av_log(avctx, AV_LOG_ERROR, "wrong picture format\n");
+ return -1;
+ }
+
+ if (av_image_check_size(s->width, s->height, 0, avctx))
+ return -1;
+ avcodec_set_dimensions(avctx, s->width, s->height);
+
+ if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
+ return ret;
+
+ p->pict_type = AV_PICTURE_TYPE_I;
+ 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. */
+ bytestream2_seek(&s->g, SGI_HEADER_SIZE, SEEK_SET);
+ if (rle) {
+ ret = read_rle_sgi(out_end, s);
+ } else {
+ ret = read_uncompressed_sgi(out_buf, s);
+ }
+
+ if (ret == 0) {
+ *got_frame = 1;
+ return avpkt->size;
+ } else {
+ return ret;
+ }
+}
+
+AVCodec ff_sgi_decoder = {
+ .name = "sgi",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .id = AV_CODEC_ID_SGI,
+ .priv_data_size = sizeof(SgiState),
+ .decode = decode_frame,
+ .long_name = NULL_IF_CONFIG_SMALL("SGI image"),
+ .capabilities = CODEC_CAP_DR1,
+};
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