SGI RLE 8-bit decoder

Signed-off-by: Peter Ross <pross@xvid.org>

1 files changed, 148 insertions, 0 deletions

diff --git a/libavcodec/sgirledec.c b/libavcodec/sgirledec.c
new file mode 100644
index 0000000000..0ce6afda82
--- /dev/null
+++ b/libavcodec/sgirledec.c
@@ -0,0 +1,148 @@
+/*
+ * SGI RLE 8-bit decoder
+ * Copyright (c) 2012 Peter Ross
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * SGI RLE 8-bit decoder
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "avcodec.h"
+#include "bytestream.h"
+
+static av_cold int sgirle_decode_init(AVCodecContext *avctx)
+{
+    avctx->pix_fmt = AV_PIX_FMT_BGR8;
+    avctx->coded_frame = avcodec_alloc_frame();
+    if (!avctx->coded_frame)
+        return AVERROR(ENOMEM);
+    return 0;
+}
+
+/**
+ * Convert SGI RGB332 pixel into PIX_FMT_BGR8
+ * SGI RGB332 is packed RGB 3:3:2, 8bpp, (msb)3R 2B 3G(lsb)
+ */
+#define RGB332_TO_BGR8(x) (((x << 3) & 0xC0) | ((x << 3) & 0x38) | ((x >> 5) & 7))
+
+static av_always_inline void memcpy_rgb332_to_bgr8(uint8_t *dst, const uint8_t *src, int size)
+{
+    int i;
+    for (i = 0; i < size; i++)
+        dst[i] = RGB332_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, int 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);
+                memset(dst + y*linesize + x, RGB332_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)
+                    break;
+                memcpy_rgb332_to_bgr8(dst + y*linesize + x, src, length);
+                INC_XY(length);
+                src += length;
+                v   -= length;
+            } while (v > 0);
+        } else {
+            av_log_ask_for_sample(avctx, "unknown opcode\n");
+            return AVERROR_PATCHWELCOME;
+        }
+    }
+    return 0;
+}
+
+static int sgirle_decode_frame(AVCodecContext *avctx,
+                            void *data, int *got_frame,
+                            AVPacket *avpkt)
+{
+    AVFrame *frame = avctx->coded_frame;
+    int ret;
+
+    frame->reference = 3;
+    frame->buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
+                          FF_BUFFER_HINTS_REUSABLE | FF_BUFFER_HINTS_READABLE;
+    ret = avctx->reget_buffer(avctx, frame);
+    if (ret < 0) {
+        av_log (avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
+        return ret;
+    }
+
+    ret = decode_sgirle8(avctx, frame->data[0], avpkt->data, avpkt->size, avctx->width, avctx->height, frame->linesize[0]);
+    if (ret < 0)
+        return ret;
+
+    *got_frame      = 1;
+    *(AVFrame*)data = *frame;
+
+    return avpkt->size;
+}
+
+static av_cold int sgirle_decode_end(AVCodecContext *avctx)
+{
+    if (avctx->coded_frame->data[0])
+        avctx->release_buffer(avctx, avctx->coded_frame);
+    av_freep(&avctx->coded_frame);
+    return 0;
+}
+
+AVCodec ff_sgirle_decoder = {
+    .name           = "sgirle",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_SGIRLE,
+    .init           = sgirle_decode_init,
+    .close          = sgirle_decode_end,
+    .decode         = sgirle_decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
+    .long_name      = NULL_IF_CONFIG_SMALL("SGI RLE 8-bit"),
+};