Andreas Rheinhardt:
> Use a small LUT instead. Improves performance.
>
> Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@outlook.com>
> ---
> libavcodec/xbmenc.c | 21 +++++++++++++++------
> 1 file changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/libavcodec/xbmenc.c b/libavcodec/xbmenc.c
> index cd8b73afa3..5231d4691d 100644
> --- a/libavcodec/xbmenc.c
> +++ b/libavcodec/xbmenc.c
> @@ -20,11 +20,9 @@
> * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
> USA
> */
>
> -#include "libavutil/reverse.h"
> #include "avcodec.h"
> #include "codec_internal.h"
> #include "encode.h"
> -#include "mathops.h"
>
> #define ANSI_MIN_READLINE 509
>
> @@ -57,14 +55,25 @@ static int xbm_encode_frame(AVCodecContext *avctx,
> AVPacket *pkt,
> buf += snprintf(buf, 39, "static unsigned char image_bits[] = {\n");
> for (i = 0, l = lineout; i < avctx->height; i++) {
> for (j = 0; j < linesize; j++) {
> - buf += snprintf(buf, 6, " 0x%02X", ff_reverse[*ptr++]);
> + // 0..15 bitreversed as chars
> + static const char lut[] = {
> + '0', '8', '4', 'C', '2', 'A', '6', 'E',
> + '1', '9', '5', 'D', '3', 'B', '7', 'F'
> + };
> + buf[0] = ' ';
> + buf[1] = '0';
> + buf[2] = 'x';
> + buf[3] = lut[*ptr & 0xF];
> + buf[4] = lut[*ptr >> 4];
> + buf += 5;
> + ptr++;
> if (--commas <= 0) {
> - buf += snprintf(buf, 2, "\n");
> + *buf++ = '\n';
> break;
> }
> - buf += snprintf(buf, 2, ",");
> + *buf++ = ',';
> if (--l <= 0) {
> - buf += snprintf(buf, 2, "\n");
> + *buf++ = '\n';
> l = lineout;
> }
> }
Will apply.
- Andreas
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