static inline void qtrle_decode_2n4bpp(QtrleContext *s, int stream_ptr, int row_ptr, int lines_to_change, int bpp) { int rle_code, i; int pixel_ptr; int row_inc = s->frame.linesize[0]; unsigned char pi[16]; /* 16 palette indices */ unsigned char *rgb = s->frame.data[0]; int pixel_limit = s->frame.linesize[0] * s->avctx->height; int num_pixels = (bpp == 4) ? 8 : 16; while (lines_to_change--) { CHECK_STREAM_PTR(2); pixel_ptr = row_ptr + (num_pixels * (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 += (num_pixels * (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 * indexes, and output them rle_code times */ CHECK_STREAM_PTR(4); for (i = num_pixels-1; i >= 0; i--) { pi[num_pixels-1-i] = (s->buf[stream_ptr] >> ((i*bpp) & 0x07)) & ((1<<bpp)-1); stream_ptr+= ((i & ((num_pixels>>2)-1)) == 0); } CHECK_PIXEL_PTR(rle_code * num_pixels); while (rle_code--) { for (i = 0; i < num_pixels; i++) rgb[pixel_ptr++] = pi[i]; } } else { /* copy the same pixel directly to output 4 times */ rle_code *= 4; CHECK_STREAM_PTR(rle_code); CHECK_PIXEL_PTR(rle_code*(num_pixels>>2)); while (rle_code--) { if(bpp == 4) { rgb[pixel_ptr++] = ((s->buf[stream_ptr]) >> 4) & 0x0f; rgb[pixel_ptr++] = (s->buf[stream_ptr++]) & 0x0f; } else { rgb[pixel_ptr++] = ((s->buf[stream_ptr]) >> 6) & 0x03; rgb[pixel_ptr++] = ((s->buf[stream_ptr]) >> 4) & 0x03; rgb[pixel_ptr++] = ((s->buf[stream_ptr]) >> 2) & 0x03; rgb[pixel_ptr++] = (s->buf[stream_ptr++]) & 0x03; } } } } row_ptr += row_inc; } }