go LOCO, courtesy of Kostya Shishkov

Originally committed as revision 3995 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 319 insertions, 0 deletions

diff --git a/libavcodec/loco.c b/libavcodec/loco.c
new file mode 100644
index 0000000000..92af609f40
--- /dev/null
+++ b/libavcodec/loco.c
@@ -0,0 +1,319 @@
+/*
+ * LOCO codec
+ * Copyright (c) 2005 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 loco.c
+ * LOCO codec.
+ */
+ 
+#include "avcodec.h"
+#include "common.h"
+#include "bitstream.h"
+#include "golomb.h"
+
+enum LOCO_MODE {LOCO_UNKN=0, LOCO_CYUY2=-1, LOCO_CRGB=-2, LOCO_CYV12=-3,
+ LOCO_YUY2=1, LOCO_UYVY=2, LOCO_RGB=3, LOCO_RGBA=4, LOCO_YV12=5};
+
+typedef struct LOCOContext{
+    AVCodecContext *avctx;
+    AVFrame pic;
+    int lossy;
+    int mode;
+} LOCOContext;
+
+typedef struct RICEContext{
+    GetBitContext gb;
+    int save, run, run2; /* internal rice decoder state */
+    int sum, count; /* sum and count for getting rice parameter */
+}RICEContext;
+
+/* could use get_sr_golomb() but is behaves differently on numbers like Rice(2, -64) */
+static inline int get_rice(GetBitContext *gb, int K)
+{
+    int i;
+    int V = 0;
+    for(i = 0; !get_bits1(gb); i++);
+    V = i;
+    for(i = 0; i < K; i++) V = (V << 1) | get_bits1(gb);
+    if(V & 1) return (V + 1) >> 1;
+    return -(V >> 1);
+}
+
+static inline int get_u_rice(GetBitContext *gb, int K)
+{
+    int i;
+    int V = 0;
+    for(i = 0; !get_bits1(gb); i++);
+    V = i;
+    for(i = 0; i < K; i++) V = (V << 1) | get_bits1(gb);
+    return V;
+}
+
+static int loco_get_rice_param(RICEContext *r)
+{
+    int cnt = 0;
+    int val = r->count;
+    
+    while(r->sum > val && cnt < 9) {
+        val <<= 1;
+        cnt++;
+    }
+    
+    return cnt;
+}
+
+static inline void loco_update_rice_param(RICEContext *r, int val)
+{
+    if (val < 0)
+        val = -val;
+    r->sum += val;
+    r->count++;
+    
+    if(r->count == 16) {
+        r->sum >>= 1;
+        r->count >>= 1;
+    }
+}
+
+static inline int loco_get_rice(RICEContext *r)
+{
+    int v;
+    
+    if (r->run > 0) { /* we have zero run */
+        r->run--;
+        return 0;
+    }
+    v = -get_rice(&r->gb, loco_get_rice_param(r));
+    if (!v) {
+        if (r->save >= 0) {
+            r->run = get_u_rice(&r->gb, 2);
+            if(r->run > 1)
+                r->save += r->run + 1;
+            else
+                r->save -= 3;
+        }
+        else
+            r->run2++;
+    } else if (r->run2 > 0) {
+        if (r->run2 > 2)
+            r->save += r->run2;
+        else
+            r->save -= 3;
+        r->run2 = 0;
+    }
+    
+    return v;
+}
+
+/* LOCO main predictor - LOCO-I/JPEG-LS predictor */
+static inline int loco_predict(uint8_t* data, int stride, int step)
+{
+    int max_ab, min_ab;
+    int a, b, c;
+    
+    a = data[-stride];
+    b = data[-step];
+    c = data[-stride - step];
+    
+    max_ab = (a > b) ? a : b;
+    min_ab = (a < b) ? a : b;
+    
+    if (c >= max_ab) return min_ab;
+    if (c <= min_ab) return max_ab;
+    return (a + b - c);
+}
+
+static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
+                             int stride, uint8_t *buf, int buf_size, int step)
+{
+    RICEContext rc;
+    int val;
+    int i, j;
+    
+    init_get_bits(&rc.gb, buf, buf_size*8);
+    rc.save = 0;
+    rc.run = 0;
+    rc.run2 = 0;
+    
+    rc.sum = 8;
+    rc.count = 1;
+    
+    /* restore top left pixel */
+    val = loco_get_rice(&rc);
+    loco_update_rice_param(&rc, val);
+    if (val < 0) val -= l->lossy;
+    if (val > 0) val += l->lossy;
+    data[0] = 128 + val;
+    /* restore top line */
+    for (i = 1; i < width; i++) {
+        val = loco_get_rice(&rc);
+        loco_update_rice_param(&rc, val);
+        if (val < 0) val -= l->lossy;
+        if (val > 0) val += l->lossy;
+        data[i * step] = data[i * step - step] + val;
+    }
+    data += stride;
+    for (j = 1; j < height; j++) {
+        /* restore left column */
+        val = loco_get_rice(&rc);
+        loco_update_rice_param(&rc, val);
+        if (val < 0) val -= l->lossy;
+        if (val > 0) val += l->lossy;
+        data[0] = data[-stride] + val;
+        /* restore all other pixels */
+        for (i = 1; i < width; i++) {
+            val = loco_get_rice(&rc);
+            loco_update_rice_param(&rc, val);
+            if (val < 0) val -= l->lossy;
+            if (val > 0) val += l->lossy;
+            data[i * step] = loco_predict(&data[i * step], stride, step) + val;
+        }
+        data += stride;
+    }
+    
+    return ((get_bits_count(&rc.gb) + 7) >> 3);
+}
+
+static int decode_frame(AVCodecContext *avctx, 
+                        void *data, int *data_size,
+                        uint8_t *buf, int buf_size)
+{
+    LOCOContext * const l = avctx->priv_data;
+    AVFrame * const p= (AVFrame*)&l->pic;
+    int decoded;
+
+    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;
+    }
+    p->key_frame = 1;
+
+    switch(l->mode) {
+    case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
+        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
+                                    p->linesize[0], buf, buf_size, 1);
+        buf += decoded; buf_size -= decoded;
+        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
+                                    p->linesize[1], buf, buf_size, 1);
+        buf += decoded; buf_size -= decoded;
+        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
+                                    p->linesize[2], buf, buf_size, 1);
+        break;
+    case LOCO_CYV12: case LOCO_YV12:
+        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
+                                    p->linesize[0], buf, buf_size, 1);
+        buf += decoded; buf_size -= decoded;
+        decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
+                                    p->linesize[1], buf, buf_size, 1);
+        buf += decoded; buf_size -= decoded;
+        decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
+                                    p->linesize[2], buf, buf_size, 1);
+        break;
+    case LOCO_CRGB: case LOCO_RGB:
+        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
+                                    p->linesize[0], buf, buf_size, 3);
+        buf += decoded; buf_size -= decoded;
+        decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
+                                    p->linesize[0], buf, buf_size, 3);
+        buf += decoded; buf_size -= decoded;
+        decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
+                                    p->linesize[0], buf, buf_size, 3);
+        break;
+    case LOCO_RGBA:
+        decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
+                                    p->linesize[0], buf, buf_size, 4);
+        buf += decoded; buf_size -= decoded;
+        decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
+                                    p->linesize[0], buf, buf_size, 4);
+        buf += decoded; buf_size -= decoded;
+        decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
+                                    p->linesize[0], buf, buf_size, 4);
+        buf += decoded; buf_size -= decoded;
+        decoded = loco_decode_plane(l, p->data[0] + 3, avctx->width, avctx->height,
+                                    p->linesize[0], buf, buf_size, 4);
+        break;
+    }
+
+    *data_size = sizeof(AVFrame);
+    *(AVFrame*)data = l->pic;
+    
+    return buf_size;
+}
+
+static int decode_init(AVCodecContext *avctx){
+    LOCOContext * const l = avctx->priv_data;
+    int version;
+
+    l->avctx = avctx;
+    if (avctx->extradata_size < 12) {
+        av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
+               avctx->extradata_size);
+        return -1;
+    }
+    version = LE_32(avctx->extradata);
+    switch(version) {
+    case 1:
+        l->lossy = 0;
+        break;
+    case 2:
+        l->lossy = LE_32(avctx->extradata + 8);
+        break;
+    default:
+        l->lossy = LE_32(avctx->extradata + 8);
+        av_log(avctx, AV_LOG_INFO, "This is LOCO codec version %i, please upload file for study\n", version);
+    }
+    
+    l->mode = LE_32(avctx->extradata + 4);
+    switch(l->mode) {
+    case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
+        avctx->pix_fmt = PIX_FMT_YUV422P;
+        break;
+    case LOCO_CRGB: case LOCO_RGB:
+        avctx->pix_fmt = PIX_FMT_BGR24;
+        break;
+    case LOCO_CYV12: case LOCO_YV12:
+        avctx->pix_fmt = PIX_FMT_YUV420P;
+        break;
+    case LOCO_RGBA:
+        avctx->pix_fmt = PIX_FMT_RGBA32;
+        break;
+    default:
+        av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
+        return -1;
+    }
+
+    return 0;
+}
+
+AVCodec loco_decoder = {
+    "loco",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_LOCO,
+    sizeof(LOCOContext),
+    decode_init,
+    NULL,
+    NULL,
+    decode_frame,
+    CODEC_CAP_DR1,
+};