ljpegenc: split bgr encoding into a separate function

libavcodec/ljpegenc.c

@@ -57,59 +57,33 @@ typedef struct LJpegEncContext {
     uint16_t (*scratch)[4];
 } LJpegEncContext;
 
-static int ljpeg_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
-                              const AVFrame *pict, int *got_packet)
+static int ljpeg_encode_bgr(AVCodecContext *avctx, PutBitContext *pb,
+                            const AVFrame *frame)
 {
     LJpegEncContext *s    = avctx->priv_data;
-    PutBitContext pb;
-    const int width  = avctx->width;
-    const int height = avctx->height;
-    const int predictor= avctx->prediction_method+1;
-    const int mb_width  = (width  + s->hsample[0] - 1) / s->hsample[0];
-    const int mb_height = (height + s->vsample[0] - 1) / s->vsample[0];
-    int max_pkt_size = FF_MIN_BUFFER_SIZE;
-    int ret, header_bits;
-
-    if (avctx->pix_fmt == AV_PIX_FMT_BGR24)
-        max_pkt_size += width * height * 3 * 3;
-    else {
-        max_pkt_size += mb_width * mb_height * 3 * 4
-                        * s->hsample[0] * s->vsample[0];
-    }
-    if ((ret = ff_alloc_packet(pkt, max_pkt_size)) < 0) {
-        av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", max_pkt_size);
-        return ret;
-    }
-
-    init_put_bits(&pb, pkt->data, pkt->size);
-
-    ff_mjpeg_encode_picture_header(avctx, &pb, &s->scantable,
-                                   s->matrix);
-
-    header_bits = put_bits_count(&pb);
-
-    if (avctx->pix_fmt == AV_PIX_FMT_BGR24) {
-        int x, y, i;
-        const int linesize = pict->linesize[0];
+    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++){
+    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);
+        uint8_t *ptr = frame->data[0] + (linesize * y);
 
-            if(pb.buf_end - pb.buf - (put_bits_count(&pb) >> 3) < width * 3 * 3) {
+        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++){
+        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;
@@ -128,12 +102,51 @@ static int ljpeg_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                 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
+                    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);
+                    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)
+{
+    LJpegEncContext *s = avctx->priv_data;
+    PutBitContext pb;
+    const int width  = avctx->width;
+    const int height = avctx->height;
+    const int predictor= avctx->prediction_method+1;
+    const int mb_width  = (width  + s->hsample[0] - 1) / s->hsample[0];
+    const int mb_height = (height + s->vsample[0] - 1) / s->vsample[0];
+    int max_pkt_size = FF_MIN_BUFFER_SIZE;
+    int ret, header_bits;
+
+    if (avctx->pix_fmt == AV_PIX_FMT_BGR24)
+        max_pkt_size += width * height * 3 * 3;
+    else {
+        max_pkt_size += mb_width * mb_height * 3 * 4
+                        * s->hsample[0] * s->vsample[0];
+    }
+    if ((ret = ff_alloc_packet(pkt, max_pkt_size)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", max_pkt_size);
+        return ret;
+    }
+
+    init_put_bits(&pb, pkt->data, pkt->size);
+
+    ff_mjpeg_encode_picture_header(avctx, &pb, &s->scantable,
+                                   s->matrix);
+
+    header_bits = put_bits_count(&pb);
+
+    if (avctx->pix_fmt == AV_PIX_FMT_BGR24) {
+        ret = ljpeg_encode_bgr(avctx, &pb, pict);
+        if (ret < 0)
+            return ret;
     }else{
         int mb_x, mb_y, i;