diff --git a/libavcodec/qtrle.c b/libavcodec/qtrle.c index 55fa98663d..1fedaccf16 100644 --- a/libavcodec/qtrle.c +++ b/libavcodec/qtrle.c @@ -74,6 +74,92 @@ static void qtrle_decode_2bpp(QtrleContext *s) static void qtrle_decode_4bpp(QtrleContext *s) { + int stream_ptr; + int header; + int start_line; + int lines_to_change; + int rle_code; + int row_ptr, pixel_ptr; + int row_inc = s->frame.linesize[0]; + unsigned char pi1, pi2, pi3, pi4, pi5, pi6, pi7, pi8; /* 8 palette indices */ + unsigned char *rgb = s->frame.data[0]; + int pixel_limit = s->frame.linesize[0] * s->avctx->height; + + /* check if this frame is even supposed to change */ + if (s->size < 8) + return; + + /* start after the chunk size */ + stream_ptr = 4; + + /* fetch the header */ + CHECK_STREAM_PTR(2); + header = BE_16(&s->buf[stream_ptr]); + stream_ptr += 2; + + /* if a header is present, fetch additional decoding parameters */ + if (header & 0x0008) { + CHECK_STREAM_PTR(8); + start_line = BE_16(&s->buf[stream_ptr]); + stream_ptr += 4; + lines_to_change = BE_16(&s->buf[stream_ptr]); + stream_ptr += 4; + } else { + start_line = 0; + lines_to_change = s->avctx->height; + } + + row_ptr = row_inc * start_line; + while (lines_to_change--) { + CHECK_STREAM_PTR(2); + pixel_ptr = row_ptr + (8 * (s->buf[stream_ptr++] - 1)); + + while ((rle_code = (signed char)s->buf[stream_ptr++]) != -1) { + if (rle_code == 0) { + /* there's another skip code in the stream */ + CHECK_STREAM_PTR(1); + pixel_ptr += (8 * (s->buf[stream_ptr++] - 1)); + } else if (rle_code < 0) { + /* decode the run length code */ + rle_code = -rle_code; + /* get the next 4 bytes from the stream, treat them as palette + * indices, and output them rle_code times */ + CHECK_STREAM_PTR(4); + pi1 = ((s->buf[stream_ptr]) >> 4) & 0x0f; + pi2 = (s->buf[stream_ptr++]) & 0x0f; + pi3 = ((s->buf[stream_ptr]) >> 4) & 0x0f; + pi4 = (s->buf[stream_ptr++]) & 0x0f; + pi5 = ((s->buf[stream_ptr]) >> 4) & 0x0f; + pi6 = (s->buf[stream_ptr++]) & 0x0f; + pi7 = ((s->buf[stream_ptr]) >> 4) & 0x0f; + pi8 = (s->buf[stream_ptr++]) & 0x0f; + + CHECK_PIXEL_PTR(rle_code * 8); + + while (rle_code--) { + rgb[pixel_ptr++] = pi1; + rgb[pixel_ptr++] = pi2; + rgb[pixel_ptr++] = pi3; + rgb[pixel_ptr++] = pi4; + rgb[pixel_ptr++] = pi5; + rgb[pixel_ptr++] = pi6; + rgb[pixel_ptr++] = pi7; + rgb[pixel_ptr++] = pi8; + } + } else { + /* copy the same pixel directly to output 4 times */ + rle_code *= 4; + CHECK_STREAM_PTR(rle_code); + CHECK_PIXEL_PTR(rle_code*2); + + while (rle_code--) { + rgb[pixel_ptr++] = ((s->buf[stream_ptr]) >> 4) & 0x0f; + rgb[pixel_ptr++] = (s->buf[stream_ptr++]) & 0x0f; + } + } + } + row_ptr += row_inc; + } } static void qtrle_decode_8bpp(QtrleContext *s) @@ -473,6 +559,12 @@ static int qtrle_decode_frame(AVCodecContext *avctx, case 4: case 36: qtrle_decode_4bpp(s); + /* make the palette available on the way out */ + 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; + } break; case 8: