Factorize out code used for MS RLE format decoding in different decoders.

Originally committed as revision 15356 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 8 insertions, 198 deletions

diff --git a/libavcodec/msrle.c b/libavcodec/msrle.c
index 4ea00f6915..0fd036618c 100644
--- a/libavcodec/msrle.c
+++ b/libavcodec/msrle.c
@@ -38,6 +38,7 @@
 
 #include "avcodec.h"
 #include "dsputil.h"
+#include "msrledec.h"
 
 typedef struct MsrleContext {
     AVCodecContext *avctx;
@@ -48,194 +49,6 @@ typedef struct MsrleContext {
 
 } MsrleContext;
 
-#define FETCH_NEXT_STREAM_BYTE() \
-    if (stream_ptr >= s->size) \
-    { \
-      av_log(s->avctx, AV_LOG_ERROR, " MS RLE: stream ptr just went out of bounds (1)\n"); \
-      return; \
-    } \
-    stream_byte = s->buf[stream_ptr++];
-
-static void msrle_decode_pal4(MsrleContext *s)
-{
-    int stream_ptr = 0;
-    unsigned char rle_code;
-    unsigned char extra_byte, odd_pixel;
-    unsigned char stream_byte;
-    int pixel_ptr = 0;
-    int row_dec = s->frame.linesize[0];
-    int row_ptr = (s->avctx->height - 1) * row_dec;
-    int frame_size = row_dec * s->avctx->height;
-    int i;
-
-    /* make the palette available */
-    memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
-    if (s->avctx->palctrl->palette_changed) {
-        s->frame.palette_has_changed = 1;
-        s->avctx->palctrl->palette_changed = 0;
-    }
-
-    while (row_ptr >= 0) {
-        FETCH_NEXT_STREAM_BYTE();
-        rle_code = stream_byte;
-        if (rle_code == 0) {
-            /* fetch the next byte to see how to handle escape code */
-            FETCH_NEXT_STREAM_BYTE();
-            if (stream_byte == 0) {
-                /* line is done, goto the next one */
-                row_ptr -= row_dec;
-                pixel_ptr = 0;
-            } else if (stream_byte == 1) {
-                /* decode is done */
-                return;
-            } else if (stream_byte == 2) {
-                /* reposition frame decode coordinates */
-                FETCH_NEXT_STREAM_BYTE();
-                pixel_ptr += stream_byte;
-                FETCH_NEXT_STREAM_BYTE();
-                row_ptr -= stream_byte * row_dec;
-        } 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) ||
-                (row_ptr < 0)) {
-                av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
-                return;
-            }
-
-            for (i = 0; i < rle_code; i++) {
-                if (pixel_ptr >= s->avctx->width)
-                    break;
-                FETCH_NEXT_STREAM_BYTE();
-                s->frame.data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
-                pixel_ptr++;
-                if (i + 1 == rle_code && odd_pixel)
-                    break;
-                if (pixel_ptr >= s->avctx->width)
-                    break;
-                s->frame.data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
-                pixel_ptr++;
-            }
-
-            // if the RLE code is odd, skip a byte in the stream
-            if (extra_byte)
-              stream_ptr++;
-            }
-        } else {
-            // decode a run of data
-            if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
-                (row_ptr < 0)) {
-                av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
-                return;
-            }
-            FETCH_NEXT_STREAM_BYTE();
-            for (i = 0; i < rle_code; i++) {
-                if (pixel_ptr >= s->avctx->width)
-                    break;
-                if ((i & 1) == 0)
-                    s->frame.data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
-                else
-                    s->frame.data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
-                pixel_ptr++;
-            }
-        }
-    }
-
-    /* one last sanity check on the way out */
-    if (stream_ptr < s->size)
-        av_log(s->avctx, AV_LOG_ERROR, " MS RLE: ended frame decode with bytes left over (%d < %d)\n",
-            stream_ptr, s->size);
-}
-
-
-
-static void msrle_decode_pal8(MsrleContext *s)
-{
-    int stream_ptr = 0;
-    unsigned char rle_code;
-    unsigned char extra_byte;
-    unsigned char stream_byte;
-    int pixel_ptr = 0;
-    int row_dec = s->frame.linesize[0];
-    int row_ptr = (s->avctx->height - 1) * row_dec;
-    int frame_size = row_dec * s->avctx->height;
-
-    /* make the palette available */
-    memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
-    if (s->avctx->palctrl->palette_changed) {
-        s->frame.palette_has_changed = 1;
-        s->avctx->palctrl->palette_changed = 0;
-    }
-
-    while (row_ptr >= 0) {
-        FETCH_NEXT_STREAM_BYTE();
-        rle_code = stream_byte;
-        if (rle_code == 0) {
-            /* fetch the next byte to see how to handle escape code */
-            FETCH_NEXT_STREAM_BYTE();
-            if (stream_byte == 0) {
-                /* line is done, goto the next one */
-                row_ptr -= row_dec;
-                pixel_ptr = 0;
-            } else if (stream_byte == 1) {
-                /* decode is done */
-                return;
-            } else if (stream_byte == 2) {
-                /* reposition frame decode coordinates */
-                FETCH_NEXT_STREAM_BYTE();
-                pixel_ptr += stream_byte;
-                FETCH_NEXT_STREAM_BYTE();
-                row_ptr -= stream_byte * row_dec;
-            } else {
-                /* copy pixels from encoded stream */
-                if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
-                    (row_ptr < 0)) {
-                    av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
-                    return;
-                }
-
-                rle_code = stream_byte;
-                extra_byte = stream_byte & 0x01;
-                if (stream_ptr + rle_code + extra_byte > s->size) {
-                    av_log(s->avctx, AV_LOG_ERROR, " MS RLE: stream ptr just went out of bounds (2)\n");
-                    return;
-                }
-
-                while (rle_code--) {
-                    FETCH_NEXT_STREAM_BYTE();
-                    s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
-                    pixel_ptr++;
-                }
-
-                /* if the RLE code is odd, skip a byte in the stream */
-                if (extra_byte)
-                    stream_ptr++;
-            }
-        } else {
-            /* decode a run of data */
-            if ((row_ptr + pixel_ptr + stream_byte > frame_size) ||
-                (row_ptr < 0)) {
-                av_log(s->avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (2)\n");
-                return;
-            }
-
-            FETCH_NEXT_STREAM_BYTE();
-
-            while(rle_code--) {
-                s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
-                pixel_ptr++;
-            }
-        }
-    }
-
-    /* one last sanity check on the way out */
-    if (stream_ptr < s->size)
-        av_log(s->avctx, AV_LOG_ERROR, " MS RLE: ended frame decode with bytes left over (%d < %d)\n",
-            stream_ptr, s->size);
-}
-
 static av_cold int msrle_decode_init(AVCodecContext *avctx)
 {
     MsrleContext *s = avctx->priv_data;
@@ -264,18 +77,15 @@ static int msrle_decode_frame(AVCodecContext *avctx,
         return -1;
     }
 
-    switch (avctx->bits_per_coded_sample) {
-        case 8:
-            msrle_decode_pal8(s);
-            break;
-        case 4:
-            msrle_decode_pal4(s);
-            break;
-        default:
-            av_log(avctx, AV_LOG_ERROR, "Don't know how to decode depth %u.\n",
-                   avctx->bits_per_coded_sample);
+    /* make the palette available */
+    memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
+    if (s->avctx->palctrl->palette_changed) {
+        s->frame.palette_has_changed = 1;
+        s->avctx->palctrl->palette_changed = 0;
     }
 
+    ff_msrle_decode(avctx, &s->frame, avctx->bits_per_coded_sample, buf, buf_size);
+
     *data_size = sizeof(AVFrame);
     *(AVFrame*)data = s->frame;