diff ffmpeg/libavcodec/bfi.c @ 10:6840f77b83aa

commit

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ffmpeg/libavcodec/bfi.c	Sun Apr 21 10:55:35 2013 +0200
@@ -0,0 +1,186 @@
+/*
+ * Brute Force & Ignorance (BFI) video decoder
+ * Copyright (c) 2008 Sisir Koppaka
+ *
+ * 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
+ * @brief Brute Force & Ignorance (.bfi) video decoder
+ * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
+ * @see http://wiki.multimedia.cx/index.php?title=BFI
+ */
+
+#include "libavutil/common.h"
+#include "avcodec.h"
+#include "bytestream.h"
+#include "internal.h"
+
+typedef struct BFIContext {
+    AVCodecContext *avctx;
+    uint8_t *dst;
+    uint32_t pal[256];
+} BFIContext;
+
+static av_cold int bfi_decode_init(AVCodecContext *avctx)
+{
+    BFIContext *bfi = avctx->priv_data;
+    avctx->pix_fmt  = AV_PIX_FMT_PAL8;
+    bfi->dst        = av_mallocz(avctx->width * avctx->height);
+    return 0;
+}
+
+static int bfi_decode_frame(AVCodecContext *avctx, void *data,
+                            int *got_frame, AVPacket *avpkt)
+{
+    AVFrame *frame = data;
+    GetByteContext g;
+    int buf_size    = avpkt->size;
+    BFIContext *bfi = avctx->priv_data;
+    uint8_t *dst    = bfi->dst;
+    uint8_t *src, *dst_offset, colour1, colour2;
+    uint8_t *frame_end = bfi->dst + avctx->width * avctx->height;
+    uint32_t *pal;
+    int i, j, ret, height = avctx->height;
+
+    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+        return ret;
+
+    bytestream2_init(&g, avpkt->data, buf_size);
+
+    /* Set frame parameters and palette, if necessary */
+    if (!avctx->frame_number) {
+        frame->pict_type = AV_PICTURE_TYPE_I;
+        frame->key_frame = 1;
+        /* Setting the palette */
+        if (avctx->extradata_size > 768) {
+            av_log(NULL, AV_LOG_ERROR, "Palette is too large.\n");
+            return AVERROR_INVALIDDATA;
+        }
+        pal = (uint32_t *)frame->data[1];
+        for (i = 0; i < avctx->extradata_size / 3; i++) {
+            int shift = 16;
+            *pal = 0xFFU << 24;
+            for (j = 0; j < 3; j++, shift -= 8)
+                *pal += ((avctx->extradata[i * 3 + j] << 2) |
+                         (avctx->extradata[i * 3 + j] >> 4)) << shift;
+            pal++;
+        }
+        memcpy(bfi->pal, frame->data[1], sizeof(bfi->pal));
+        frame->palette_has_changed = 1;
+    } else {
+        frame->pict_type = AV_PICTURE_TYPE_P;
+        frame->key_frame = 0;
+        frame->palette_has_changed = 0;
+        memcpy(frame->data[1], bfi->pal, sizeof(bfi->pal));
+    }
+
+    bytestream2_skip(&g, 4); // Unpacked size, not required.
+
+    while (dst != frame_end) {
+        static const uint8_t lentab[4] = { 0, 2, 0, 1 };
+        unsigned int byte   = bytestream2_get_byte(&g), av_uninit(offset);
+        unsigned int code   = byte >> 6;
+        unsigned int length = byte & ~0xC0;
+
+        if (!bytestream2_get_bytes_left(&g)) {
+            av_log(avctx, AV_LOG_ERROR,
+                   "Input resolution larger than actual frame.\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        /* Get length and offset (if required) */
+        if (length == 0) {
+            if (code == 1) {
+                length = bytestream2_get_byte(&g);
+                offset = bytestream2_get_le16(&g);
+            } else {
+                length = bytestream2_get_le16(&g);
+                if (code == 2 && length == 0)
+                    break;
+            }
+        } else {
+            if (code == 1)
+                offset = bytestream2_get_byte(&g);
+        }
+
+        /* Do boundary check */
+        if (dst + (length << lentab[code]) > frame_end)
+            break;
+
+        switch (code) {
+        case 0:                // normal chain
+            if (length >= bytestream2_get_bytes_left(&g)) {
+                av_log(avctx, AV_LOG_ERROR, "Frame larger than buffer.\n");
+                return AVERROR_INVALIDDATA;
+            }
+            bytestream2_get_buffer(&g, dst, length);
+            dst += length;
+            break;
+        case 1:                // back chain
+            dst_offset = dst - offset;
+            length    *= 4;     // Convert dwords to bytes.
+            if (dst_offset < bfi->dst)
+                break;
+            while (length--)
+                *dst++ = *dst_offset++;
+            break;
+        case 2:                // skip chain
+            dst += length;
+            break;
+        case 3:                // fill chain
+            colour1 = bytestream2_get_byte(&g);
+            colour2 = bytestream2_get_byte(&g);
+            while (length--) {
+                *dst++ = colour1;
+                *dst++ = colour2;
+            }
+            break;
+        }
+    }
+
+    src = bfi->dst;
+    dst = frame->data[0];
+    while (height--) {
+        memcpy(dst, src, avctx->width);
+        src += avctx->width;
+        dst += frame->linesize[0];
+    }
+    *got_frame = 1;
+
+    return buf_size;
+}
+
+static av_cold int bfi_decode_close(AVCodecContext *avctx)
+{
+    BFIContext *bfi = avctx->priv_data;
+    av_free(bfi->dst);
+    return 0;
+}
+
+AVCodec ff_bfi_decoder = {
+    .name           = "bfi",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_BFI,
+    .priv_data_size = sizeof(BFIContext),
+    .init           = bfi_decode_init,
+    .close          = bfi_decode_close,
+    .decode         = bfi_decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
+    .long_name      = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
+};