diff options
| -rw-r--r-- | libavcodec/msrle.c | 107 |
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); |