Silicon Graphics RLE 8-bit video decoder

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

1 files changed, 160 insertions, 0 deletions

diff --git a/libavcodec/sgirledec.c b/libavcodec/sgirledec.c
new file mode 100644
index 0000000000..d7bc5a9ea4
--- /dev/null
+++ b/libavcodec/sgirledec.c
@@ -0,0 +1,160 @@
+/*
+ * Silicon Graphics RLE 8-bit video decoder
+ * Copyright (c) 2012 Peter Ross
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * Silicon Graphics RLE 8-bit video decoder
+ * @note Data is packed in rbg323 with rle, contained in mv or mov.
+ * The algorithm and pixfmt are subtly different from SGI images.
+ */
+
+#include "libavutil/common.h"
+
+#include "avcodec.h"
+#include "internal.h"
+
+typedef struct SGIRLEContext {
+    AVFrame *frame;
+} SGIRLEContext;
+
+static av_cold int sgirle_decode_init(AVCodecContext *avctx)
+{
+    SGIRLEContext *s = avctx->priv_data;
+    avctx->pix_fmt = AV_PIX_FMT_BGR8;
+    s->frame = av_frame_alloc();
+    if (!s->frame)
+        return AVERROR(ENOMEM);
+    return 0;
+}
+
+/**
+ * Convert SGI RBG323 pixel into AV_PIX_FMT_BGR8
+ * SGI RGB data is packed as 8bpp, (msb)3R 2B 3G(lsb)
+ */
+#define RBG323_TO_BGR8(x) (((x << 3) & 0xC0) |                                \
+                           ((x << 3) & 0x38) |                                \
+                           ((x >> 5) & 7))
+static av_always_inline
+void rbg323_to_bgr8(uint8_t *dst, const uint8_t *src, int size)
+{
+    int i;
+    for (i = 0; i < size; i++)
+        dst[i] = RBG323_TO_BGR8(src[i]);
+}
+
+/**
+ * @param[out] dst Destination buffer
+ * @param[in] src  Source buffer
+ * @param src_size Source buffer size (bytes)
+ * @param width    Width of destination buffer (pixels)
+ * @param height   Height of destination buffer (pixels)
+ * @param linesize Line size of destination buffer (bytes)
+ *
+ * @return <0 on error
+ */
+static int decode_sgirle8(AVCodecContext *avctx, uint8_t *dst,
+                          const uint8_t *src, int src_size,
+                          int width, int height, ptrdiff_t linesize)
+{
+    const uint8_t *src_end = src + src_size;
+    int x = 0, y = 0;
+
+#define INC_XY(n)                                                             \
+    x += n;                                                                   \
+    if (x >= width) {                                                         \
+        y++;                                                                  \
+        if (y >= height)                                                      \
+            return 0;                                                         \
+        x = 0;                                                                \
+    }
+
+    while (src_end - src >= 2) {
+        uint8_t v = *src++;
+        if (v > 0 && v < 0xC0) {
+            do {
+                int length = FFMIN(v, width - x);
+                if (length <= 0)
+                    break;
+                memset(dst + y * linesize + x, RBG323_TO_BGR8(*src), length);
+                INC_XY(length);
+                v -= length;
+            } while (v > 0);
+            src++;
+        } else if (v >= 0xC1) {
+            v -= 0xC0;
+            do {
+                int length = FFMIN3(v, width - x, src_end - src);
+                if (src_end - src < length || length <= 0)
+                    break;
+                rbg323_to_bgr8(dst + y * linesize + x, src, length);
+                INC_XY(length);
+                src += length;
+                v   -= length;
+            } while (v > 0);
+        } else {
+            av_log(avctx, AV_LOG_ERROR, "Invalid opcode %d.\n", v);
+            return AVERROR_INVALIDDATA;
+        }
+    }
+    return 0;
+}
+
+static int sgirle_decode_frame(AVCodecContext *avctx, void *data,
+                               int *got_frame, AVPacket *avpkt)
+{
+    SGIRLEContext *s = avctx->priv_data;
+    int ret;
+
+    if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
+        return ret;
+
+    ret = decode_sgirle8(avctx, s->frame->data[0], avpkt->data, avpkt->size,
+                         avctx->width, avctx->height, s->frame->linesize[0]);
+    if (ret < 0)
+        return ret;
+
+    *got_frame = 1;
+    if ((ret = av_frame_ref(data, s->frame)) < 0)
+        return ret;
+
+    return avpkt->size;
+}
+
+static av_cold int sgirle_decode_end(AVCodecContext *avctx)
+{
+    SGIRLEContext *s = avctx->priv_data;
+
+    av_frame_free(&s->frame);
+
+    return 0;
+}
+
+AVCodec ff_sgirle_decoder = {
+    .name           = "sgirle",
+    .long_name      = NULL_IF_CONFIG_SMALL("Silicon Graphics RLE 8-bit video"),
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_SGIRLE,
+    .priv_data_size = sizeof(SGIRLEContext),
+    .init           = sgirle_decode_init,
+    .close          = sgirle_decode_end,
+    .decode         = sgirle_decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
+};