avcodec/dvbsubdec: Compute scoretab without iterating over pixels multiple times...
[ffmpeg.git] / libavcodec / msrledec.c
index 06777d7..f0cbde6 100644 (file)
 #include "avcodec.h"
 #include "msrledec.h"
 
-static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
+static int msrle_decode_pal4(AVCodecContext *avctx, AVFrame *pic,
                              GetByteContext *gb)
 {
     unsigned char rle_code;
     unsigned char extra_byte, odd_pixel;
     unsigned char stream_byte;
-    unsigned int pixel_ptr = 0;
-    int row_dec = pic->linesize[0];
-    int row_ptr = (avctx->height - 1) * row_dec;
-    int frame_size = row_dec * avctx->height;
+    int pixel_ptr = 0;
+    int line = avctx->height - 1;
     int i;
 
-    while (row_ptr >= 0) {
+    while (line >= 0 && pixel_ptr <= avctx->width) {
         if (bytestream2_get_bytes_left(gb) <= 0) {
             av_log(avctx, AV_LOG_ERROR,
-                   "MS RLE: bytestream overrun, %d rows left\n",
-                   row_ptr);
+                   "MS RLE: bytestream overrun, %dx%d left\n",
+                   avctx->width - pixel_ptr, line);
             return AVERROR_INVALIDDATA;
         }
         rle_code = stream_byte = bytestream2_get_byteu(gb);
@@ -55,7 +53,7 @@ static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
             stream_byte = bytestream2_get_byte(gb);
             if (stream_byte == 0) {
                 /* line is done, goto the next one */
-                row_ptr -= row_dec;
+                line--;
                 pixel_ptr = 0;
             } else if (stream_byte == 1) {
                 /* decode is done */
@@ -65,13 +63,13 @@ static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
                 stream_byte = bytestream2_get_byte(gb);
                 pixel_ptr += stream_byte;
                 stream_byte = bytestream2_get_byte(gb);
-                row_ptr -= stream_byte * row_dec;
+                line -= stream_byte;
             } else {
                 // copy pixels from encoded stream
                 odd_pixel =  stream_byte & 1;
                 rle_code = (stream_byte + 1) / 2;
                 extra_byte = rle_code & 0x01;
-                if (row_ptr + pixel_ptr + stream_byte > frame_size ||
+                if (pixel_ptr + 2*rle_code - odd_pixel > avctx->width ||
                     bytestream2_get_bytes_left(gb) < rle_code) {
                     av_log(avctx, AV_LOG_ERROR,
                            "MS RLE: frame/stream ptr just went out of bounds (copy)\n");
@@ -82,13 +80,13 @@ static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
                     if (pixel_ptr >= avctx->width)
                         break;
                     stream_byte = bytestream2_get_byteu(gb);
-                    pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
+                    pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte >> 4;
                     pixel_ptr++;
                     if (i + 1 == rle_code && odd_pixel)
                         break;
                     if (pixel_ptr >= avctx->width)
                         break;
-                    pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
+                    pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte & 0x0F;
                     pixel_ptr++;
                 }
 
@@ -98,9 +96,9 @@ static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
             }
         } else {
             // decode a run of data
-            if (row_ptr + pixel_ptr + stream_byte > frame_size) {
+            if (pixel_ptr + rle_code > avctx->width + 1) {
                 av_log(avctx, AV_LOG_ERROR,
-                       "MS RLE: frame ptr just went out of bounds (run)\n");
+                       "MS RLE: frame ptr just went out of bounds (run) %d %d %d\n", pixel_ptr, rle_code, avctx->width);
                 return AVERROR_INVALIDDATA;
             }
             stream_byte = bytestream2_get_byte(gb);
@@ -108,9 +106,9 @@ static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
                 if (pixel_ptr >= avctx->width)
                     break;
                 if ((i & 1) == 0)
-                    pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
+                    pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte >> 4;
                 else
-                    pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
+                    pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte & 0x0F;
                 pixel_ptr++;
             }
         }
@@ -128,7 +126,7 @@ static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
 }
 
 
-static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic,
+static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVFrame *pic,
                                    int depth, GetByteContext *gb)
 {
     uint8_t *output, *output_end;
@@ -211,8 +209,8 @@ static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic,
             switch(depth){
             case  8:
                 pix[0] = bytestream2_get_byte(gb);
-                for(i = 0; i < p1; i++)
-                        *output++ = pix[0];
+                memset(output, pix[0], p1);
+                output += p1;
                 break;
             case 16:
                 pix16  = bytestream2_get_le16(gb);
@@ -248,7 +246,7 @@ static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic,
 }
 
 
-int ff_msrle_decode(AVCodecContext *avctx, AVPicture *pic,
+int ff_msrle_decode(AVCodecContext *avctx, AVFrame *pic,
                     int depth, GetByteContext *gb)
 {
     switch(depth){