native QPEG video decoder, courtesy of Konstantin Shishkov

Originally committed as revision 3688 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 303 insertions, 0 deletions

diff --git a/libavcodec/qpeg.c b/libavcodec/qpeg.c
new file mode 100644
index 0000000000..bb6467b331
--- /dev/null
+++ b/libavcodec/qpeg.c
@@ -0,0 +1,303 @@
+/*
+ * QPEG codec
+ * Copyright (c) 2004 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+ 
+/**
+ * @file qpeg.c
+ * QPEG codec.
+ */
+ 
+#include "avcodec.h"
+#include "mpegvideo.h"
+
+typedef struct QpegContext{
+    AVCodecContext *avctx;
+    AVFrame pic;
+    uint8_t *refdata;
+} QpegContext;
+
+static void qpeg_decode_intra(uint8_t *src, uint8_t *dst, int size,
+			    int stride, int width, int height)
+{
+    int i;
+    int code;
+    int c0, c1;
+    int run, copy;
+    int filled = 0;
+    
+    height--;
+    dst = dst + height * stride;
+    
+    while(size > 0) {
+	code = *src++;
+	size--;
+	run = copy = 0;
+	if(code == 0xFC) /* end-of-picture code */
+	    break;
+	if(code >= 0xF8) { /* very long run */
+	    c0 = *src++;
+	    c1 = *src++;
+	    size -= 2;
+	    run = ((code & 0x7) << 16) + (c0 << 8) + c1 + 2;
+	} else if (code >= 0xF0) { /* long run */
+	    c0 = *src++;
+	    size--;
+	    run = ((code & 0xF) << 8) + c0 + 2;
+	} else if (code >= 0xE0) { /* short run */
+	    run = (code & 0x1F) + 2;
+	} else if (code >= 0xC0) { /* very long copy */
+	    c0 = *src++;
+	    c1 = *src++;
+	    size -= 2;
+	    copy = ((code & 0x3F) << 16) + (c0 << 8) + c1 + 1;
+	} else if (code >= 0x80) { /* long copy */
+	    c0 = *src++;
+	    size--;
+	    copy = ((code & 0x7F) << 8) + c0 + 1;
+	} else { /* short copy */
+	    copy = code + 1;
+	}
+	
+	/* perform actual run or copy */
+	if(run) {
+	    int p;
+	    
+	    p = *src++;
+	    size--;
+	    for(i = 0; i < run; i++) {
+		dst[filled++] = p;
+		if (filled >= width) {
+		    filled = 0;
+		    dst -= stride;
+		}
+	    }
+	} else {
+	    for(i = 0; i < copy; i++) {
+		dst[filled++] = *src++;
+		if (filled >= width) {
+		    filled = 0;
+		    dst -= stride;
+		}
+	    }
+	    size -= copy;
+	}
+    }
+}
+
+static int qpeg_table_h[16] = 
+ { 0x00, 0x20, 0x20, 0x20, 0x18, 0x10, 0x10, 0x20, 0x10, 0x08, 0x18, 0x08, 0x08, 0x18, 0x10, 0x04};
+static int qpeg_table_w[16] =
+ { 0x00, 0x20, 0x18, 0x08, 0x18, 0x10, 0x20, 0x10, 0x08, 0x10, 0x20, 0x20, 0x08, 0x10, 0x18, 0x04};
+ 
+/* Decodes delta frames */
+static void qpeg_decode_inter(uint8_t *src, uint8_t *dst, int size,
+			    int stride, int width, int height,
+			    int delta, uint8_t *ctable, uint8_t *refdata)
+{
+    int i, j;
+    int code;
+    int filled = 0;
+    uint8_t *blkdata;
+    
+    /* copy prev frame */
+    for(i = 0; i < height; i++)
+	memcpy(refdata + (i * width), dst + (i * stride), width);
+    
+    blkdata = src - 0x86;
+    height--;
+    dst = dst + height * stride;
+
+    while(size > 0) {
+	code = *src++;
+	size--;
+	
+	if(delta) {
+	    /* motion compensation */
+	    while((code & 0xF0) == 0xF0) {
+		if(delta == 1) {
+		    int me_idx;
+		    int me_w, me_h, me_x, me_y;
+		    uint8_t *me_plane;
+		    int corr, val;
+		    
+		    /* get block size by index */
+		    me_idx = code & 0xF;
+		    me_w = qpeg_table_w[me_idx];
+		    me_h = qpeg_table_h[me_idx];
+		    
+		    /* extract motion vector */
+		    corr = *src++;
+		    size--;
+
+		    val = corr >> 4;
+		    if(val > 7)
+			val -= 16;
+		    me_x = val;
+		    
+		    val = corr & 0xF;
+		    if(val > 7)
+			val -= 16;
+		    me_y = val;
+		    
+		    /* do motion compensation */
+		    me_plane = refdata + (filled + me_x) + (height - me_y) * width;
+		    for(j = 0; j < me_h; j++) {
+			for(i = 0; i < me_w; i++)
+			    dst[filled + i - (j * stride)] = me_plane[i - (j * width)];
+		    }
+		}
+		code = *src++;
+		size--;
+	    }
+	}
+	
+	if(code == 0xE0) /* end-of-picture code */
+	    break;
+	if(code > 0xE0) { /* run code: 0xE1..0xFF */
+	    int p;
+
+	    code &= 0x1F;
+	    p = *src++;
+	    size--;
+	    for(i = 0; i <= code; i++) {
+		dst[filled++] = p;
+		if(filled >= width) {
+		    filled = 0;
+		    dst -= stride;
+		    height--;
+		}
+	    }
+	} else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */
+	    code &= 0x1F;
+	    
+	    for(i = 0; i <= code; i++) {
+		dst[filled++] = *src++;
+		if(filled >= width) {
+		    filled = 0;
+		    dst -= stride;
+		    height--;
+		}
+	    }
+	    size -= code + 1;
+	} else if(code >= 0x80) { /* skip code: 0x80..0xBF */
+	    int skip;
+	    
+	    code &= 0x3F;
+	    /* codes 0x80 and 0x81 are actually escape codes,
+	       skip value minus constant is in the next byte */
+	    if(!code)
+		skip = (*src++) + 64;
+	    else if(code == 1)
+		skip = (*src++) + 320;
+	    else
+		skip = code;
+	    filled += skip;
+	    while( filled >= width) {
+		filled -= width;
+		dst -= stride;
+		height--;
+	    }
+	} else {
+	    /* zero code treated as one-pixel skip */
+	    if(code)
+		dst[filled++] = ctable[code & 0x7F];
+	    else
+		filled++;
+	    if(filled >= width) {
+		filled = 0;
+		dst -= stride;
+		height--;
+	    }
+	}
+    }
+}
+
+static int decode_frame(AVCodecContext *avctx, 
+                        void *data, int *data_size,
+                        uint8_t *buf, int buf_size)
+{
+    QpegContext * const a = avctx->priv_data;
+    AVFrame * const p= (AVFrame*)&a->pic;
+    uint8_t* outdata;
+    int delta;
+    
+    /* special case for last picture */
+    if (buf_size == 0) {
+        return 0;
+    }
+
+    if(p->data[0])
+        avctx->release_buffer(avctx, p);
+
+    p->reference= 0;
+    if(avctx->get_buffer(avctx, p) < 0){
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return -1;
+    }
+    outdata = a->pic.data[0];
+    if(buf[0x85] == 0x10) {
+	qpeg_decode_intra(buf+0x86, outdata, buf_size - 0x86, a->pic.linesize[0], avctx->width, avctx->height);
+    } else {
+	delta = buf[0x85];
+	qpeg_decode_inter(buf+0x86, outdata, buf_size - 0x86, a->pic.linesize[0], avctx->width, avctx->height, delta, buf + 4, a->refdata);
+    }
+
+    /* make the palette available on the way out */
+    memcpy(a->pic.data[1], a->avctx->palctrl->palette, AVPALETTE_SIZE);
+    if (a->avctx->palctrl->palette_changed) {
+        a->pic.palette_has_changed = 1;
+        a->avctx->palctrl->palette_changed = 0;
+    }
+
+    *data_size = sizeof(AVFrame);
+    *(AVFrame*)data = a->pic;
+    
+    return buf_size;
+}
+
+static int decode_init(AVCodecContext *avctx){
+    QpegContext * const a = avctx->priv_data;
+    
+    a->avctx = avctx;
+    avctx->pix_fmt= PIX_FMT_PAL8;
+    avctx->has_b_frames = 0;
+    a->pic.data[0] = NULL;
+    a->refdata = av_malloc(avctx->width * avctx->height);
+
+    return 0;
+}
+
+static int decode_end(AVCodecContext *avctx){
+    QpegContext * const a = avctx->priv_data;
+
+    av_free(a->refdata);
+    return 0;
+}
+
+AVCodec qpeg_decoder = {
+    "qpeg",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_QPEG,
+    sizeof(QpegContext),
+    decode_init,
+    NULL,
+    decode_end,
+    decode_frame,
+    CODEC_CAP_DR1,
+};