implemented Id Quake II CIN support

Originally committed as revision 2339 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 278 insertions, 0 deletions

diff --git a/libavcodec/idcinvideo.c b/libavcodec/idcinvideo.c
new file mode 100644
index 0000000000..2a6ae360f8
--- /dev/null
+++ b/libavcodec/idcinvideo.c
@@ -0,0 +1,278 @@
+/*
+ * Id Quake II CIN Video Decoder
+ * Copyright (C) 2003 the ffmpeg project
+ *
+ * This library 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 of the License, or (at your option) any later version.
+ *
+ * This library 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 this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+/**
+ * @file idcinvideo.c
+ * Id Quake II Cin Video Decoder by Dr. Tim Ferguson
+ * For more information about the Id CIN format, visit:
+ *   http://www.csse.monash.edu.au/~timf/
+ *
+ * This video decoder outputs PAL8 colorspace data.
+ *
+ * Id CIN video is purely Huffman-coded, intraframe-only codec. It achieves
+ * a little more compression by exploiting the fact that adjacent pixels
+ * tend to be similar.
+ *
+ * Note that this decoder could use ffmpeg's optimized VLC facilities
+ * rather than naive, tree-based Huffman decoding. However, there are 256
+ * Huffman tables. Plus, the VLC bit coding order is right -> left instead
+ * or left -> right, so all of the bits would have to be reversed. Further,
+ * the original Quake II implementation likely used a similar naive
+ * decoding algorithm and it worked fine on much lower spec machines.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "common.h"
+#include "avcodec.h"
+#include "dsputil.h"
+
+#define HUFFMAN_TABLE_SIZE 64 * 1024
+#define HUF_TOKENS 256
+#define PALETTE_COUNT 256
+
+typedef struct
+{
+  int count;
+  unsigned char used;
+  int children[2];
+} hnode_t;
+
+typedef struct IdcinContext {
+
+    AVCodecContext *avctx;
+    DSPContext dsp;
+    AVFrame frame;
+
+    unsigned char *buf;
+    int size;
+
+    unsigned char palette[PALETTE_COUNT * 4];
+
+    hnode_t huff_nodes[256][HUF_TOKENS*2];
+    int num_huff_nodes[256];
+
+} IdcinContext;
+
+/*
+ * Find the lowest probability node in a Huffman table, and mark it as
+ * being assigned to a higher probability.
+ * Returns the node index of the lowest unused node, or -1 if all nodes
+ * are used.
+ */
+static int huff_smallest_node(hnode_t *hnodes, int num_hnodes) {
+    int i;
+    int best, best_node;
+
+    best = 99999999;
+    best_node = -1;
+    for(i = 0; i < num_hnodes; i++) {
+        if(hnodes[i].used)
+            continue;
+        if(!hnodes[i].count)
+            continue;
+        if(hnodes[i].count < best) {
+            best = hnodes[i].count;
+            best_node = i;
+        }
+    }
+
+    if(best_node == -1)
+        return -1;
+    hnodes[best_node].used = 1;
+    return best_node;
+}
+
+/*
+ * Build the Huffman tree using the generated/loaded probabilities histogram.
+ *
+ * On completion:
+ *  huff_nodes[prev][i < HUF_TOKENS] - are the nodes at the base of the tree.
+ *  huff_nodes[prev][i >= HUF_TOKENS] - are used to construct the tree.
+ *  num_huff_nodes[prev] - contains the index to the root node of the tree.
+ *    That is: huff_nodes[prev][num_huff_nodes[prev]] is the root node.
+ */
+static void huff_build_tree(IdcinContext *s, int prev) {
+    hnode_t *node, *hnodes;
+     int num_hnodes, i;
+
+    num_hnodes = HUF_TOKENS;
+    hnodes = s->huff_nodes[prev];
+    for(i = 0; i < HUF_TOKENS * 2; i++)
+        hnodes[i].used = 0;
+
+    while (1) {
+        node = &hnodes[num_hnodes];             /* next free node */
+
+        /* pick two lowest counts */
+        node->children[0] = huff_smallest_node(hnodes, num_hnodes);
+        if(node->children[0] == -1)
+            break;      /* reached the root node */
+
+        node->children[1] = huff_smallest_node(hnodes, num_hnodes);
+        if(node->children[1] == -1)
+            break;      /* reached the root node */
+
+        /* combine nodes probability for new node */
+        node->count = hnodes[node->children[0]].count +
+        hnodes[node->children[1]].count;
+        num_hnodes++;
+    }
+
+    s->num_huff_nodes[prev] = num_hnodes - 1;
+}
+
+static int idcin_decode_init(AVCodecContext *avctx)
+{
+    IdcinContext *s = (IdcinContext *)avctx->priv_data;
+    int i, j, histogram_index = 0;
+    unsigned char *histograms;
+
+    s->avctx = avctx;
+    avctx->pix_fmt = PIX_FMT_PAL8;
+    avctx->has_b_frames = 0;
+    dsputil_init(&s->dsp, avctx);
+
+    /* make sure the Huffman tables make it */
+    if (s->avctx->extradata_size != HUFFMAN_TABLE_SIZE) {
+        printf("  Id CIN video: expected extradata size of %d\n", HUFFMAN_TABLE_SIZE);
+        return -1;
+    }
+
+    /* build the 256 Huffman decode trees */
+    histograms = (unsigned char *)s->avctx->extradata;
+    for (i = 0; i < 256; i++) {
+        for(j = 0; j < HUF_TOKENS; j++)
+            s->huff_nodes[i][j].count = histograms[histogram_index++];
+        huff_build_tree(s, i);
+    }
+
+    s->frame.data[0] = NULL;
+
+    return 0;
+}
+
+static void idcin_decode_vlcs(IdcinContext *s)
+{
+    hnode_t *hnodes;
+    long x, y;
+    int prev;
+    unsigned char v = 0;
+    int bit_pos, node_num, dat_pos;
+
+    prev = bit_pos = dat_pos = 0;
+    for (y = 0; y < (s->frame.linesize[0] * s->avctx->height);
+        y += s->frame.linesize[0]) {
+        for (x = y; x < y + s->avctx->width; x++) {
+            node_num = s->num_huff_nodes[prev];
+            hnodes = s->huff_nodes[prev];
+
+            while(node_num >= HUF_TOKENS) {
+                if(!bit_pos) {
+                    if(dat_pos > s->size) {
+                        printf("Huffman decode error.\n");
+                        return;
+                    }
+                    bit_pos = 8;
+                    v = s->buf[dat_pos++];
+                }
+
+                node_num = hnodes[node_num].children[v & 0x01];
+                v = v >> 1;
+                bit_pos--;
+            }
+
+            s->frame.data[0][x] = node_num;
+            prev = node_num;
+        }
+    }
+}
+
+static int idcin_decode_frame(AVCodecContext *avctx,
+                              void *data, int *data_size,
+                              uint8_t *buf, int buf_size)
+{
+    IdcinContext *s = (IdcinContext *)avctx->priv_data;
+    AVPaletteControl *palette_control = 
+        (AVPaletteControl *)avctx->extradata;
+    int i;
+    unsigned int *palette32;
+    int palette_index = 0;
+    unsigned char r, g, b;
+
+    s->buf = buf;
+    s->size = buf_size;
+
+    if (palette_control->palette_changed) {
+        palette32 = (unsigned int *)s->palette;
+        for (i = 0; i < PALETTE_COUNT; i++) {
+            r = palette_control->palette[palette_index++] * 1;
+            g = palette_control->palette[palette_index++] * 1;
+            b = palette_control->palette[palette_index++] * 1;
+            palette32[i] = (r << 16) | (g << 8) | (b);
+        }
+        palette_control->palette_changed = 0;
+    }
+
+    if (s->frame.data[0])
+        avctx->release_buffer(avctx, &s->frame);
+
+    if (avctx->get_buffer(avctx, &s->frame)) {
+        printf ("  Id CIN Video: get_buffer() failed\n");
+        return -1;
+    }
+
+    idcin_decode_vlcs(s);
+
+    /* make the palette available on the way out */
+    memcpy(s->frame.data[1], s->palette, PALETTE_COUNT * 4);
+
+    *data_size = sizeof(AVFrame);
+    *(AVFrame*)data = s->frame;
+
+    /* report that the buffer was completely consumed */
+    return buf_size;
+}
+
+static int idcin_decode_end(AVCodecContext *avctx)
+{
+    IdcinContext *s = (IdcinContext *)avctx->priv_data;
+
+    if (s->frame.data[0])
+        avctx->release_buffer(avctx, &s->frame);
+
+    return 0;
+}
+
+AVCodec idcin_decoder = {
+    "idcinvideo",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_IDCIN,
+    sizeof(IdcinContext),
+    idcin_decode_init,
+    NULL,
+    idcin_decode_end,
+    idcin_decode_frame,
+    CODEC_CAP_DR1,
+};
+