[Ffmpeg-devel] [RFC] ZMBV encoder

Kostya kostya.shishkov
Mon Dec 4 07:13:57 CET 2006


Here is my ZMBV encoder for encoding palettized videos.
-------------- next part --------------
Index: libavcodec/zmbvenc.c
===================================================================
--- libavcodec/zmbvenc.c	(revision 0)
+++ libavcodec/zmbvenc.c	(revision 0)
@@ -0,0 +1,341 @@
+/*
+ * Zip Motion Blocks Video (ZMBV) encoder
+ * Copyright (c) 2006 Konstantin Shishkov
+ *
+ * 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 zmbvenc.c
+ * Zip Motion Blocks Video encoder
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "common.h"
+#include "avcodec.h"
+#include "dsputil.h"
+
+#ifdef CONFIG_ZLIB
+#include <zlib.h>
+#endif
+
+#define ZMBV_KEYFRAME 1
+#define ZMBV_DELTAPAL 2
+
+#define ZMBV_BLOCK 16
+
+/*
+ * Encoder context
+ */
+typedef struct ZmbvEncContext {
+    AVCodecContext *avctx;
+    AVFrame pic;
+
+    int width, height;
+    uint8_t *comp_buf, *work_buf;
+    uint8_t pal[768];
+    uint32_t pal2[256]; //for quick comparisons
+    uint8_t *prev;
+    int pstride;
+    int comp_size;
+    int keyint, curfrm;
+#ifdef CONFIG_ZLIB
+    z_stream zstream;
+#endif
+} ZmbvEncContext;
+
+/** Block comparing function
+ * XXX should be optimized and moved to DSPContext
+ * TODO handle out of edge ME
+ */
+int block_cmp(uint8_t *src, int stride, uint8_t *src2, int stride2, int bw, int bh)
+{
+    int sum = 0;
+    int i, j;
+    for(j = 0; j < bh; j++){
+        for(i = 0; i < bw; i++)
+            sum += src[i] ^ src2[i];
+        src += stride;
+        src2 += stride2;
+    }
+    return sum;
+}
+
+static int encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data)
+{
+    ZmbvEncContext * const c = (ZmbvEncContext *)avctx->priv_data;
+    AVFrame *pict = data;
+    AVFrame * const p = &c->pic;
+    uint8_t *src, *prev;
+    uint32_t *palptr;
+#ifdef CONFIG_ZLIB
+    int zret = Z_OK; // Zlib return code
+#endif
+    int len = 0;
+    int keyframe, chpal;
+    int fl;
+    int work_size = 0;
+    int bw, bh;
+    int i, j;
+
+    keyframe = !c->curfrm;
+    c->curfrm = c->curfrm++;
+    if(c->curfrm == c->keyint)
+        c->curfrm = 0;
+    *p = *pict;
+    p->pict_type= keyframe ? FF_I_TYPE : FF_P_TYPE;
+    p->key_frame= keyframe;
+    chpal = !keyframe && memcmp(c->pal2, p->data[1], 1024);
+
+    fl = (keyframe ? ZMBV_KEYFRAME : 0) | (chpal ? ZMBV_DELTAPAL : 0);
+    *buf++ = fl; len++;
+    if(keyframe){
+        deflateReset(&c->zstream);
+        *buf++ = 0; len++; // hi ver
+        *buf++ = 1; len++; // lo ver
+        *buf++ = 1; len++; // comp
+        *buf++ = 4; len++; // format - 8bpp
+        *buf++ = ZMBV_BLOCK; len++; // block width
+        *buf++ = ZMBV_BLOCK; len++; // block height
+    }
+    palptr = (uint32_t*)p->data[1];
+    src = p->data[0];
+    prev = c->prev;
+    if(chpal){
+        uint8_t tpal[3];
+        for(i = 0; i < 256; i++){
+            tpal[0] = (palptr[i] >> 16) & 0xFF;
+            tpal[1] = (palptr[i] >>  8) & 0xFF;
+            tpal[2] = palptr[i] & 0xFF;
+            c->work_buf[work_size++] = tpal[0] ^ c->pal[i * 3 + 0];
+            c->work_buf[work_size++] = tpal[1] ^ c->pal[i * 3 + 1];
+            c->work_buf[work_size++] = tpal[2] ^ c->pal[i * 3 + 1];
+            c->pal[i * 3 + 0] = tpal[0];
+            c->pal[i * 3 + 1] = tpal[1];
+            c->pal[i * 3 + 2] = tpal[2];
+        }
+        memcpy(c->pal2, p->data[1], 1024);
+    }
+    if(keyframe){
+        for(i = 0; i < 256; i++){
+            c->pal[i*3 + 0] = (palptr[i] >> 16) & 0xFF;
+            c->pal[i*3 + 1] = (palptr[i] >>  8) & 0xFF;
+            c->pal[i*3 + 2] = palptr[i] & 0xFF;
+        }
+        memcpy(c->work_buf, c->pal, 768);
+        memcpy(c->pal2, p->data[1], 1024);
+        work_size = 768;
+        for(i = 0; i < avctx->height; i++){
+            memcpy(c->work_buf + work_size, src, avctx->width);
+            src += p->linesize[0];
+            work_size += avctx->width;
+        }
+    }else{
+        int x, y, bh2, bw2;
+        uint8_t *tsrc, *tprev;
+        uint8_t *mv;
+        int bmvx, bmvy, bv, tx, ty, tv, dx, dy;
+
+        bw = (avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
+        bh = (avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
+        mv = c->work_buf + work_size;
+        memset(c->work_buf + work_size, 0, (bw * bh * 2 + 3) & ~3);
+        work_size += (bw * bh * 2 + 3) & ~3;
+        /* for now just XOR'ing */
+        for(y = 0; y < avctx->height; y += ZMBV_BLOCK) {
+            bh2 = FFMIN(avctx->height - y, ZMBV_BLOCK);
+            for(x = 0; x < avctx->width; x += ZMBV_BLOCK, mv += 2) {
+                bw2 = FFMIN(avctx->width - x, ZMBV_BLOCK);
+
+                tsrc = src + x;
+                tprev = prev + x;
+
+                bmvx = bmvy = 0;
+                bv = block_cmp(tsrc, p->linesize[0], tprev, c->pstride, ZMBV_BLOCK, ZMBV_BLOCK);
+                if(bv) for(ty = FFMAX(y - 16, 0); ty < FFMIN(y + 16, avctx->height - ZMBV_BLOCK); ty++){
+                    for(tx = FFMAX(x - 16, 0); tx < FFMIN(x + 16, avctx->width - ZMBV_BLOCK); tx++){
+                        if(tx == x && ty == y) continue; // we already tested this block
+                        dx = tx - x;
+                        dy = ty - y;
+                        tv = block_cmp(tsrc, p->linesize[0], tprev + dx + dy*c->pstride, c->pstride, ZMBV_BLOCK, ZMBV_BLOCK);
+                        if(tv < bv){
+                            bv = tv;
+                            bmvx = dx;
+                            bmvy = dy;
+                            if(!bv) break;
+                        }
+                    }
+                    if(!bv) break;
+                }
+                mv[0] = (bmvx << 1) | !!bv;
+                mv[1] = bmvy << 1;
+                tprev += bmvx + bmvy * c->pstride;
+                if(bv){
+                    for(j = 0; j < bh2; j++){
+                        for(i = 0; i < bw2; i++)
+                            c->work_buf[work_size++] = tsrc[i] ^ tprev[i];
+                        tsrc += p->linesize[0];
+                        tprev += c->pstride;
+                    }
+                }
+            }
+            src += p->linesize[0] * ZMBV_BLOCK;
+            prev += c->pstride * ZMBV_BLOCK;
+        }
+    }
+    /* save the previous frame */
+    src = p->data[0];
+    prev = c->prev;
+    for(i = 0; i < avctx->height; i++){
+        memcpy(prev, src, avctx->width);
+        prev += c->pstride;
+        src += p->linesize[0];
+    }
+
+#ifdef CONFIG_ZLIB
+    c->zstream.next_in = c->work_buf;
+    c->zstream.avail_in = work_size;
+    c->zstream.total_in = 0;
+
+    c->zstream.next_out = c->comp_buf;
+    c->zstream.avail_out = c->comp_size;
+    c->zstream.total_out = 0;
+    if((zret = deflate(&c->zstream, Z_SYNC_FLUSH)) != Z_OK){
+        av_log(avctx, AV_LOG_ERROR, "Error compressing data\n");
+        return -1;
+    }
+
+    memcpy(buf, c->comp_buf, c->zstream.total_out);
+    return len + c->zstream.total_out;
+#else
+    return -1;
+#endif
+}
+
+
+/*
+ *
+ * Init zmbv encoder
+ *
+ */
+static int encode_init(AVCodecContext *avctx)
+{
+    ZmbvEncContext * const c = (ZmbvEncContext *)avctx->priv_data;
+    int zret; // Zlib return code
+    int lvl = 9;
+
+    c->avctx = avctx;
+    avctx->has_b_frames = 0;
+
+    c->pic.data[0] = NULL;
+    c->width = avctx->width;
+    c->height = avctx->height;
+    c->curfrm = 0;
+    c->keyint = avctx->keyint_min;
+
+    if(avctx->compression_level >= 0)
+        lvl = avctx->compression_level;
+    if(lvl < 0 || lvl > 9){
+        av_log(avctx, AV_LOG_ERROR, "Compression level should be 0-9, not %i\n", lvl);
+        return 1;
+    }
+
+    if (avctx->pix_fmt != PIX_FMT_PAL8) {
+        av_log(avctx, AV_LOG_ERROR, "Only pal8 format is supported.\n");
+        return 1;
+    }
+    if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
+        return 1;
+    }
+
+#ifdef CONFIG_ZLIB
+    // Needed if zlib unused or init aborted before deflateInit
+    memset(&(c->zstream), 0, sizeof(z_stream));
+#else
+    av_log(avctx, AV_LOG_ERROR, "Zlib support not compiled.\n");
+    return 1;
+#endif
+    c->comp_size = avctx->width * avctx->height + 1024 +
+        ((avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * ((avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * 2 + 4;
+    if ((c->work_buf = av_malloc(c->comp_size)) == NULL) {
+        av_log(avctx, AV_LOG_ERROR, "Can't allocate work buffer.\n");
+        return 1;
+    }
+    /* Conservative upper bound taken from zlib v1.2.1 source via lcl.c */
+    c->comp_size = c->comp_size + ((c->comp_size + 7) >> 3) +
+                           ((c->comp_size + 63) >> 6) + 11;
+
+    /* Allocate compression buffer */
+    if ((c->comp_buf = av_malloc(c->comp_size)) == NULL) {
+        av_log(avctx, AV_LOG_ERROR, "Can't allocate compression buffer.\n");
+        return 1;
+    }
+    c->pstride = (avctx->width + 15) & ~15;
+    if ((c->prev = av_malloc(c->pstride * avctx->height)) == NULL) {
+        av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n");
+        return 1;
+    }
+
+#ifdef CONFIG_ZLIB
+    c->zstream.zalloc = Z_NULL;
+    c->zstream.zfree = Z_NULL;
+    c->zstream.opaque = Z_NULL;
+    zret = deflateInit(&(c->zstream), lvl);
+    if (zret != Z_OK) {
+        av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
+        return 1;
+    }
+#endif
+
+    return 0;
+}
+
+
+
+/*
+ *
+ * Uninit zmbv decoder
+ *
+ */
+static int encode_end(AVCodecContext *avctx)
+{
+    ZmbvEncContext * const c = (ZmbvEncContext *)avctx->priv_data;
+
+    av_freep(&c->comp_buf);
+    av_freep(&c->work_buf);
+
+#ifdef CONFIG_ZLIB
+    deflateEnd(&(c->zstream));
+#endif
+    av_freep(&c->prev);
+
+    return 0;
+}
+
+AVCodec zmbv_encoder = {
+    "zmbv",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_ZMBV,
+    sizeof(ZmbvEncContext),
+    encode_init,
+    encode_frame,
+    encode_end
+};
+
Index: libavcodec/allcodecs.c
===================================================================
--- libavcodec/allcodecs.c	(revision 7203)
+++ libavcodec/allcodecs.c	(working copy)
@@ -155,7 +155,7 @@
     REGISTER_ENCODER(XVID, xvid);
 #endif
     REGISTER_ENCDEC (ZLIB, zlib);
-    REGISTER_DECODER(ZMBV, zmbv);
+    REGISTER_ENCDEC (ZMBV, zmbv);
 
     /* audio codecs */
 #ifdef CONFIG_FAAD
Index: libavcodec/Makefile
===================================================================
--- libavcodec/Makefile	(revision 7203)
+++ libavcodec/Makefile	(working copy)
@@ -167,6 +167,7 @@
 OBJS-$(CONFIG_ZLIB_DECODER)            += lcl.o
 OBJS-$(CONFIG_ZLIB_ENCODER)            += lcl.o
 OBJS-$(CONFIG_ZMBV_DECODER)            += zmbv.o
+OBJS-$(CONFIG_ZMBV_ENCODER)            += zmbvenc.o
 
 OBJS-$(CONFIG_PCM_S32LE_DECODER)       += pcm.o
 OBJS-$(CONFIG_PCM_S32LE_ENCODER)       += pcm.o
Index: libavcodec/avcodec.h
===================================================================
--- libavcodec/avcodec.h	(revision 7203)
+++ libavcodec/avcodec.h	(working copy)
@@ -2303,6 +2303,7 @@
 extern AVCodec bmp_decoder;
 extern AVCodec mmvideo_decoder;
 extern AVCodec zmbv_decoder;
+extern AVCodec zmbv_encoder;
 extern AVCodec avs_decoder;
 extern AVCodec smacker_decoder;
 extern AVCodec smackaud_decoder;



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