ljpegenc: split bgr encoding into a separate function

libavcodec/ljpegenc.c

@@ -57,6 +57,61 @@ typedef struct LJpegEncContext {
     uint16_t (*scratch)[4];
 } LJpegEncContext;
 
+static int ljpeg_encode_bgr(AVCodecContext *avctx, PutBitContext *pb,
+                            const AVFrame *frame)
+{
+    LJpegEncContext *s    = avctx->priv_data;
+    const int width       = frame->width;
+    const int height      = frame->height;
+    const int linesize    = frame->linesize[0];
+    uint16_t (*buffer)[4] = s->scratch;
+    const int predictor   = avctx->prediction_method+1;
+    int left[3], top[3], topleft[3];
+    int x, y, i;
+
+    for (i = 0; i < 3; i++)
+        buffer[0][i] = 1 << (9 - 1);
+
+    for (y = 0; y < height; y++) {
+        const int modified_predictor = y ? predictor : 1;
+        uint8_t *ptr = frame->data[0] + (linesize * y);
+
+        if (pb->buf_end - pb->buf - (put_bits_count(pb) >> 3) < width * 3 * 3) {
+            av_log(avctx, AV_LOG_ERROR, "encoded frame too large\n");
+            return -1;
+        }
+
+        for (i = 0; i < 3; i++)
+            top[i]= left[i]= topleft[i]= buffer[0][i];
+
+        for (x = 0; x < width; x++) {
+            buffer[x][1] =  ptr[3 * x + 0] -     ptr[3 * x + 1] + 0x100;
+            buffer[x][2] =  ptr[3 * x + 2] -     ptr[3 * x + 1] + 0x100;
+            buffer[x][0] = (ptr[3 * x + 0] + 2 * ptr[3 * x + 1] + ptr[3 * x + 2]) >> 2;
+
+            for (i = 0; i < 3; i++) {
+                int pred, diff;
+
+                PREDICT(pred, topleft[i], top[i], left[i], modified_predictor);
+
+                topleft[i] = top[i];
+                top[i]     = buffer[x+1][i];
+
+                left[i]    = buffer[x][i];
+
+                diff       = ((left[i] - pred + 0x100) & 0x1FF) - 0x100;
+
+                if (i == 0)
+                    ff_mjpeg_encode_dc(pb, diff, s->huff_size_dc_luminance, s->huff_code_dc_luminance); //FIXME ugly
+                else
+                    ff_mjpeg_encode_dc(pb, diff, s->huff_size_dc_chrominance, s->huff_code_dc_chrominance);
+            }
+        }
+    }
+
+    return 0;
+}
+
 static int ljpeg_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                               const AVFrame *pict, int *got_packet)
 {
@@ -89,51 +144,9 @@ static int ljpeg_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
     header_bits = put_bits_count(&pb);
 
     if (avctx->pix_fmt == AV_PIX_FMT_BGR24) {
-        int x, y, i;
-        const int linesize = pict->linesize[0];
-        uint16_t (*buffer)[4] = s->scratch;
-        int left[3], top[3], topleft[3];
-
-        for(i=0; i<3; i++){
-            buffer[0][i]= 1 << (9 - 1);
-        }
-
-        for(y = 0; y < height; y++) {
-            const int modified_predictor= y ? predictor : 1;
-            uint8_t *ptr = pict->data[0] + (linesize * y);
-
-            if(pb.buf_end - pb.buf - (put_bits_count(&pb) >> 3) < width * 3 * 3) {
-                av_log(avctx, AV_LOG_ERROR, "encoded frame too large\n");
-                return -1;
-            }
-
-            for(i=0; i<3; i++){
-                top[i]= left[i]= topleft[i]= buffer[0][i];
-            }
-            for(x = 0; x < width; x++) {
-                buffer[x][1] =  ptr[3 * x + 0] -     ptr[3 * x + 1] + 0x100;
-                buffer[x][2] =  ptr[3 * x + 2] -     ptr[3 * x + 1] + 0x100;
-                buffer[x][0] = (ptr[3 * x + 0] + 2 * ptr[3 * x + 1] + ptr[3 * x + 2]) >> 2;
-
-                for(i=0;i<3;i++) {
-                    int pred, diff;
-
-                    PREDICT(pred, topleft[i], top[i], left[i], modified_predictor);
-
-                    topleft[i]= top[i];
-                    top[i]= buffer[x+1][i];
-
-                    left[i]= buffer[x][i];
-
-                    diff= ((left[i] - pred + 0x100)&0x1FF) - 0x100;
-
-                    if(i==0)
-                        ff_mjpeg_encode_dc(&pb, diff, s->huff_size_dc_luminance, s->huff_code_dc_luminance); //FIXME ugly
-                    else
-                        ff_mjpeg_encode_dc(&pb, diff, s->huff_size_dc_chrominance, s->huff_code_dc_chrominance);
-                }
-            }
-        }
+        ret = ljpeg_encode_bgr(avctx, &pb, pict);
+        if (ret < 0)
+            return ret;
     }else{
         int mb_x, mb_y, i;