[Ffmpeg-devel] [RFC] KMVC decoder

Kostya kostya.shishkov
Sun Apr 2 16:47:07 CEST 2006


Here is KVMC decoder (codec used in Worms games). This is not a final version, there are samples from some version of Worms that cannot be played by DOS player, my decoder plays them but palette is not fine.
Thanks to Reimar for showing interest and providing some help.

Please test it on available samples (from MPHQ, for example) as my Internet access is no good.

But there's a catch: I could decode samples (logo1.avi and mine.avi from MPHQ) only after remuxing. My old FFmpeg build (4747) can demux them, fresh one can't. Seems to be the problem with not ignoring 'strf' 'pads' header.
-------------- next part --------------
diff -ru --exclude CVS /home/kst/cvs-get/ffmpeg/libavcodec/allcodecs.c ./libavcodec/allcodecs.c
--- /home/kst/cvs-get/ffmpeg/libavcodec/allcodecs.c	2006-03-21 19:32:36.000000000 +0200
+++ ./libavcodec/allcodecs.c	2006-04-02 10:20:09.000000000 +0300
@@ -282,6 +282,9 @@
 #ifdef CONFIG_LOCO_DECODER
     register_avcodec(&loco_decoder);
 #endif //CONFIG_LOCO_DECODER
+#ifdef CONFIG_KMVC_DECODER
+    register_avcodec(&kmvc_decoder);
+#endif //CONFIG_KMVC_DECODER
 #ifdef CONFIG_WNV1_DECODER
     register_avcodec(&wnv1_decoder);
 #endif //CONFIG_WNV1_DECODER
diff -ru --exclude CVS /home/kst/cvs-get/ffmpeg/libavcodec/avcodec.h ./libavcodec/avcodec.h
--- /home/kst/cvs-get/ffmpeg/libavcodec/avcodec.h	2006-03-21 19:32:36.000000000 +0200
+++ ./libavcodec/avcodec.h	2006-04-02 10:20:52.000000000 +0300
@@ -119,6 +119,7 @@
     CODEC_ID_ZMBV,
     CODEC_ID_AVS,
     CODEC_ID_SMACKVIDEO,
+    CODEC_ID_KMVC,
 
     /* various pcm "codecs" */
     CODEC_ID_PCM_S16LE= 0x10000,
@@ -2239,6 +2240,7 @@
 extern AVCodec bmp_decoder;
 extern AVCodec mmvideo_decoder;
 extern AVCodec zmbv_decoder;
+extern AVCodec kmvc_decoder;
 extern AVCodec avs_decoder;
 extern AVCodec smacker_decoder;
 extern AVCodec smackaud_decoder;
diff -ru --exclude CVS /home/kst/cvs-get/ffmpeg/libavcodec/kmvc.c ./libavcodec/kmvc.c
--- /home/kst/cvs-get/ffmpeg/libavcodec/kmvc.c	2006-04-02 16:52:03.000000000 +0300
+++ ./libavcodec/kmvc.c	2006-04-02 16:55:36.000000000 +0300
@@ -0,0 +1,394 @@
+/*
+ * KMVC decoder
+ * Copyright (c) 2006 Konstantin Shishkov
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ */
+
+/**
+ * @file kmvc.c
+ * Karl Morton's Video Codec decoder
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "common.h"
+#include "avcodec.h"
+
+#define KMVC_KEYFRAME 0x80
+#define KMVC_PALETTE  0x40
+#define KMVC_METHOD   0x0F
+
+/*
+ * Decoder context
+ */
+typedef struct KmvcContext {
+    AVCodecContext *avctx;
+    AVFrame pic;
+
+    int setpal;
+    int palsize;
+    uint32_t pal[256];
+    uint8_t *cur, *prev;
+    uint8_t *frm0, *frm1;
+} KmvcContext;
+
+typedef struct BitBuf {
+    int bits;
+    int bitbuf;
+} BitBuf;
+
+#define BLK(data, x, y)  data[(x) + (y) * 320]
+
+#define kmvc_init_getbits(bb, src)  bb.bits = 7; bb.bitbuf = *src++;
+
+#define kmvc_getbit(bb, src, res) {\
+    res = 0; \
+    if (bb.bitbuf & (1 << bb.bits)) res = 1; \
+    bb.bits--; \
+    if(bb.bits == -1) { \
+        bb.bitbuf = *src++; \
+        bb.bits = 7; \
+    } \
+}
+
+static void kmvc_decode_intra_8x8(KmvcContext * ctx, uint8_t * src, int w, int h)
+{
+    BitBuf bb;
+    int res, val;
+    int i, j;
+    int bx, by;
+    int l0x, l1x, l0y, l1y;
+    int mx, my;
+
+    kmvc_init_getbits(bb, src);
+
+    for (by = 0; by < h; by += 8)
+        for (bx = 0; bx < w; bx += 8) {
+            kmvc_getbit(bb, src, res);
+            if (!res) {         // fill whole 8x8 block
+                val = *src++;
+                for (i = 0; i < 64; i++)
+                    BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
+            } else {            // handle four 4x4 subblocks
+                for (i = 0; i < 4; i++) {
+                    l0x = bx + (i & 1) * 4;
+                    l0y = by + (i & 2) * 2;
+                    kmvc_getbit(bb, src, res);
+                    if (!res) {
+                        kmvc_getbit(bb, src, res);
+                        if (!res) {     // fill whole 4x4 block
+                            val = *src++;
+                            for (j = 0; j < 16; j++)
+                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
+                        } else {        // copy block from already decoded place
+                            val = *src++;
+                            mx = val & 0xF;
+                            my = val >> 4;
+                            for (j = 0; j < 16; j++)
+                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
+                                    BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
+                        }
+                    } else {    // descend to 2x2 sub-sub-blocks
+                        for (j = 0; j < 4; j++) {
+                            l1x = l0x + (j & 1) * 2;
+                            l1y = l0y + (j & 2);
+                            kmvc_getbit(bb, src, res);
+                            if (!res) {
+                                kmvc_getbit(bb, src, res);
+                                if (!res) {     // fill whole 2x2 block
+                                    val = *src++;
+                                    BLK(ctx->cur, l1x, l1y) = val;
+                                    BLK(ctx->cur, l1x + 1, l1y) = val;
+                                    BLK(ctx->cur, l1x, l1y + 1) = val;
+                                    BLK(ctx->cur, l1x + 1, l1y + 1) = val;
+                                } else {        // copy block from already decoded place
+                                    val = *src++;
+                                    mx = val & 0xF;
+                                    my = val >> 4;
+                                    BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
+                                    BLK(ctx->cur, l1x + 1, l1y) =
+                                        BLK(ctx->cur, l1x + 1 - mx, l1y - my);
+                                    BLK(ctx->cur, l1x, l1y + 1) =
+                                        BLK(ctx->cur, l1x - mx, l1y + 1 - my);
+                                    BLK(ctx->cur, l1x + 1, l1y + 1) =
+                                        BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
+                                }
+                            } else {    // read values for block
+                                BLK(ctx->cur, l1x, l1y) = *src++;
+                                BLK(ctx->cur, l1x + 1, l1y) = *src++;
+                                BLK(ctx->cur, l1x, l1y + 1) = *src++;
+                                BLK(ctx->cur, l1x + 1, l1y + 1) = *src++;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+}
+
+static void kmvc_decode_inter_8x8(KmvcContext * ctx, uint8_t * src, int w, int h)
+{
+    BitBuf bb;
+    int res, val;
+    int i, j;
+    int bx, by;
+    int l0x, l1x, l0y, l1y;
+    int mx, my;
+
+    kmvc_init_getbits(bb, src);
+
+    for (by = 0; by < h; by += 8)
+        for (bx = 0; bx < w; bx += 8) {
+            kmvc_getbit(bb, src, res);
+            if (!res) {
+                kmvc_getbit(bb, src, res);
+                if (!res) {     // fill whole 8x8 block
+                    val = *src++;
+                    for (i = 0; i < 64; i++)
+                        BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
+                } else {        // copy block from previous frame
+                    for (i = 0; i < 64; i++)
+                        BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
+                            BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
+                }
+            } else {            // handle four 4x4 subblocks
+                for (i = 0; i < 4; i++) {
+                    l0x = bx + (i & 1) * 4;
+                    l0y = by + (i & 2) * 2;
+                    kmvc_getbit(bb, src, res);
+                    if (!res) {
+                        kmvc_getbit(bb, src, res);
+                        if (!res) {     // fill whole 4x4 block
+                            val = *src++;
+                            for (j = 0; j < 16; j++)
+                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
+                        } else {        // copy block
+                            val = *src++;
+                            mx = (val & 0xF) - 8;
+                            my = (val >> 4) - 8;
+                            for (j = 0; j < 16; j++)
+                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
+                                    BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
+                        }
+                    } else {    // descend to 2x2 sub-sub-blocks
+                        for (j = 0; j < 4; j++) {
+                            l1x = l0x + (j & 1) * 2;
+                            l1y = l0y + (j & 2);
+                            kmvc_getbit(bb, src, res);
+                            if (!res) {
+                                kmvc_getbit(bb, src, res);
+                                if (!res) {     // fill whole 2x2 block
+                                    val = *src++;
+                                    BLK(ctx->cur, l1x, l1y) = val;
+                                    BLK(ctx->cur, l1x + 1, l1y) = val;
+                                    BLK(ctx->cur, l1x, l1y + 1) = val;
+                                    BLK(ctx->cur, l1x + 1, l1y + 1) = val;
+                                } else {        // copy block
+                                    val = *src++;
+                                    mx = (val & 0xF) - 8;
+                                    my = (val >> 4) - 8;
+                                    BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
+                                    BLK(ctx->cur, l1x + 1, l1y) =
+                                        BLK(ctx->prev, l1x + 1 + mx, l1y + my);
+                                    BLK(ctx->cur, l1x, l1y + 1) =
+                                        BLK(ctx->prev, l1x + mx, l1y + 1 + my);
+                                    BLK(ctx->cur, l1x + 1, l1y + 1) =
+                                        BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
+                                }
+                            } else {    // read values for block
+                                BLK(ctx->cur, l1x, l1y) = *src++;
+                                BLK(ctx->cur, l1x + 1, l1y) = *src++;
+                                BLK(ctx->cur, l1x, l1y + 1) = *src++;
+                                BLK(ctx->cur, l1x + 1, l1y + 1) = *src++;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+}
+
+static int decode_frame(AVCodecContext * avctx, void *data, int *data_size, uint8_t * buf,
+                        int buf_size)
+{
+    KmvcContext *const ctx = (KmvcContext *) avctx->priv_data;
+    uint8_t *out, *src;
+    int i;
+    int header;
+    int blocksize;
+
+    if (ctx->pic.data[0])
+        avctx->release_buffer(avctx, &ctx->pic);
+
+    ctx->pic.reference = 1;
+    ctx->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
+    if (avctx->get_buffer(avctx, &ctx->pic) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return -1;
+    }
+
+    header = buf[0];
+    buf++;
+
+    if (header & KMVC_KEYFRAME) {
+        ctx->pic.key_frame = 1;
+        ctx->pic.pict_type = FF_I_TYPE;
+    } else {
+        ctx->pic.key_frame = 0;
+        ctx->pic.pict_type = FF_P_TYPE;
+    }
+
+    if (header & KMVC_PALETTE) {
+        ctx->pic.palette_has_changed = 1;
+        // palette starts from index 1 and has 127 entries
+        for (i = 1; i <= ctx->palsize; i++) {
+            ctx->pal[i] = (buf[0] << 16) | (buf[1] << 8) | buf[2];
+            buf += 3;
+        }
+    }
+
+    if (ctx->setpal) {
+        ctx->setpal = 0;
+        ctx->pic.palette_has_changed = 1;
+    }
+
+    /* make the palette available on the way out */
+    memcpy(ctx->pic.data[1], ctx->pal, 1024);
+
+    blocksize = *buf++;
+
+    if (blocksize != 8) {
+        av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
+        return -1;
+    }
+    memset(ctx->cur, 0, 320 * 200);
+    switch (header & KMVC_METHOD) {
+    case 3:
+        kmvc_decode_intra_8x8(ctx, buf, avctx->width, avctx->height);
+        break;
+    case 4:
+        kmvc_decode_inter_8x8(ctx, buf, avctx->width, avctx->height);
+        break;
+    default:
+        av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
+        return -1;
+    }
+
+    out = ctx->pic.data[0];
+    src = ctx->cur;
+    for (i = 0; i < avctx->height; i++) {
+        memcpy(out, src, avctx->width);
+        src += 320;
+        out += ctx->pic.linesize[0];
+    }
+
+    /* flip buffers */
+    if (ctx->cur == ctx->frm0) {
+        ctx->cur = ctx->frm1;
+        ctx->prev = ctx->frm0;
+    } else {
+        ctx->cur = ctx->frm0;
+        ctx->prev = ctx->frm1;
+    }
+
+    *data_size = sizeof(AVFrame);
+    *(AVFrame *) data = ctx->pic;
+
+    /* always report that the buffer was completely consumed */
+    return buf_size;
+}
+
+
+
+/*
+ * Init kmvc decoder
+ */
+static int decode_init(AVCodecContext * avctx)
+{
+    KmvcContext *const c = (KmvcContext *) avctx->priv_data;
+    int i;
+
+    c->avctx = avctx;
+    avctx->has_b_frames = 0;
+
+    c->pic.data[0] = NULL;
+
+    if (avctx->width > 320 || avctx->height > 200) {
+        av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
+        return -1;
+    }
+
+    c->frm0 = av_mallocz(320 * 200);
+    c->frm1 = av_mallocz(320 * 200);
+    c->cur = c->frm0;
+    c->prev = c->frm1;
+
+    for (i = 0; i < 256; i++) {
+        c->pal[i] = i * 0x10101;
+    }
+
+    if (avctx->extradata_size < 12) {
+        av_log(NULL, 0, "Extradata missing, decoding may not work properly...\n");
+        c->palsize = 127;
+    } else {
+        c->palsize = LE_16(avctx->extradata + 10);
+    }
+
+    if (avctx->extradata_size == 1036) {        // palette in extradata
+        uint8_t *src = avctx->extradata + 12;
+        for (i = 0; i < 256; i++) {
+            c->pal[i] = LE_32(src);
+            src += 4;
+        }
+        c->setpal = 1;
+    }
+
+    avctx->pix_fmt = PIX_FMT_PAL8;
+
+    return 0;
+}
+
+
+
+/*
+ * Uninit kmvc decoder
+ */
+static int decode_end(AVCodecContext * avctx)
+{
+    KmvcContext *const c = (KmvcContext *) avctx->priv_data;
+
+    if (c->frm0)
+        av_free(c->frm0);
+    if (c->frm1)
+        av_free(c->frm1);
+    if (c->pic.data[0])
+        avctx->release_buffer(avctx, &c->pic);
+
+    return 0;
+}
+
+AVCodec kmvc_decoder = {
+    "kmvc",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_KMVC,
+    sizeof(KmvcContext),
+    decode_init,
+    NULL,
+    decode_end,
+    decode_frame
+};
diff -ru --exclude CVS /home/kst/cvs-get/ffmpeg/libavcodec/Makefile ./libavcodec/Makefile
--- /home/kst/cvs-get/ffmpeg/libavcodec/Makefile	2006-03-21 19:32:36.000000000 +0200
+++ ./libavcodec/Makefile	2006-04-02 10:19:25.000000000 +0300
@@ -98,6 +98,9 @@
 ifeq ($(CONFIG_INTERPLAY_VIDEO_DECODER),yes)
     OBJS+= interplayvideo.o
 endif
+ifeq ($(CONFIG_KMVC_DECODER),yes)
+    OBJS+= kmvc.o
+endif
 ifneq ($(CONFIG_MSZH_DECODER)$(CONFIG_ZLIB_DECODER)$(CONFIG_ZLIB_ENCODER),)
     OBJS+= lcl.o
 endif
diff -ru --exclude CVS /home/kst/cvs-get/ffmpeg/libavformat/avienc.c ./libavformat/avienc.c
--- /home/kst/cvs-get/ffmpeg/libavformat/avienc.c	2006-03-02 22:44:35.000000000 +0200
+++ ./libavformat/avienc.c	2006-04-02 10:24:29.000000000 +0300
@@ -200,6 +200,7 @@
     { CODEC_ID_TRUEMOTION2, MKTAG('T', 'M', '2', '0') },
     { CODEC_ID_CSCD, MKTAG('C', 'S', 'C', 'D') },
     { CODEC_ID_ZMBV, MKTAG('Z', 'M', 'B', 'V') },
+    { CODEC_ID_KMVC, MKTAG('K', 'M', 'V', 'C') },
     { CODEC_ID_RAWVIDEO, 0 },
     { CODEC_ID_NONE, 0 },
 };



More information about the ffmpeg-devel mailing list