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-rw-r--r--libavcodec/msrle.c107
1 files changed, 106 insertions, 1 deletions
diff --git a/libavcodec/msrle.c b/libavcodec/msrle.c
index 5422d9be2a..f7819cb951 100644
--- a/libavcodec/msrle.c
+++ b/libavcodec/msrle.c
@@ -56,6 +56,101 @@ typedef struct MsrleContext {
} \
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;
@@ -188,7 +283,17 @@ static int msrle_decode_frame(AVCodecContext *avctx,
memcpy(s->frame.data[0], s->prev_frame.data[0],
s->frame.linesize[0] * s->avctx->height);
- msrle_decode_pal8(s);
+ switch (avctx->bits_per_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_sample);
+ }
if (s->prev_frame.data[0])
avctx->release_buffer(avctx, &s->prev_frame);