[FFmpeg-cvslog] avcodec/wnv1: Move temporary variables from context to stack
Andreas Rheinhardt
git at videolan.org
Sun Aug 30 04:44:04 EEST 2020
ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Sat Aug 29 17:14:18 2020 +0200| [099bc252c69a6300e7eb03e245c4228703b334f2] | committer: Andreas Rheinhardt
avcodec/wnv1: Move temporary variables from context to stack
Here it even leads to the complete removal of the context.
Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=099bc252c69a6300e7eb03e245c4228703b334f2
---
libavcodec/wnv1.c | 40 +++++++++++++++++-----------------------
1 file changed, 17 insertions(+), 23 deletions(-)
diff --git a/libavcodec/wnv1.c b/libavcodec/wnv1.c
index 857807a951..b5cd0f0f0c 100644
--- a/libavcodec/wnv1.c
+++ b/libavcodec/wnv1.c
@@ -30,11 +30,6 @@
#include "internal.h"
-typedef struct WNV1Context {
- int shift;
- GetBitContext gb;
-} WNV1Context;
-
static const uint16_t code_tab[16][2] = {
{ 0x17F, 9 }, { 0xBF, 8 }, { 0x5F, 7 }, { 0x2F, 6 }, { 0x17, 5 }, { 0x0B, 4 }, { 0x005, 3 },
{ 0x000, 1 },
@@ -45,26 +40,26 @@ static const uint16_t code_tab[16][2] = {
static VLC code_vlc;
/* returns modified base_value */
-static inline int wnv1_get_code(WNV1Context *w, int base_value)
+static inline int wnv1_get_code(GetBitContext *gb, int shift, int base_value)
{
- int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1);
+ int v = get_vlc2(gb, code_vlc.table, CODE_VLC_BITS, 1);
if (v == 15)
- return get_bits(&w->gb, 8 - w->shift) << w->shift;
+ return get_bits(gb, 8 - shift) << shift;
else
- return base_value + ((v - 7U) << w->shift);
+ return base_value + ((v - 7U) << shift);
}
static int decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
- WNV1Context * const l = avctx->priv_data;
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
AVFrame * const p = data;
+ GetBitContext gb;
unsigned char *Y,*U,*V;
- int i, j, ret;
+ int i, j, ret, shift;
int prev_y = 0, prev_u = 0, prev_v = 0;
if (buf_size < 8 + avctx->height * (avctx->width/2)/8) {
@@ -76,24 +71,24 @@ static int decode_frame(AVCodecContext *avctx,
return ret;
p->key_frame = 1;
- if ((ret = init_get_bits8(&l->gb, buf + 8, buf_size - 8)) < 0)
+ if ((ret = init_get_bits8(&gb, buf + 8, buf_size - 8)) < 0)
return ret;
if (buf[2] >> 4 == 6)
- l->shift = 2;
+ shift = 2;
else {
- l->shift = 8 - (buf[2] >> 4);
- if (l->shift > 4) {
+ shift = 8 - (buf[2] >> 4);
+ if (shift > 4) {
avpriv_request_sample(avctx,
"Unknown WNV1 frame header value %i",
buf[2] >> 4);
- l->shift = 4;
+ shift = 4;
}
- if (l->shift < 1) {
+ if (shift < 1) {
avpriv_request_sample(avctx,
"Unknown WNV1 frame header value %i",
buf[2] >> 4);
- l->shift = 1;
+ shift = 1;
}
}
@@ -102,10 +97,10 @@ static int decode_frame(AVCodecContext *avctx,
V = p->data[2];
for (j = 0; j < avctx->height; j++) {
for (i = 0; i < avctx->width / 2; i++) {
- Y[i * 2] = wnv1_get_code(l, prev_y);
- prev_u = U[i] = wnv1_get_code(l, prev_u);
- prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]);
- prev_v = V[i] = wnv1_get_code(l, prev_v);
+ Y[i * 2] = wnv1_get_code(&gb, shift, prev_y);
+ prev_u = U[i] = wnv1_get_code(&gb, shift, prev_u);
+ prev_y = Y[(i * 2) + 1] = wnv1_get_code(&gb, shift, Y[i * 2]);
+ prev_v = V[i] = wnv1_get_code(&gb, shift, prev_v);
}
Y += p->linesize[0];
U += p->linesize[1];
@@ -138,7 +133,6 @@ AVCodec ff_wnv1_decoder = {
.long_name = NULL_IF_CONFIG_SMALL("Winnov WNV1"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_WNV1,
- .priv_data_size = sizeof(WNV1Context),
.init = decode_init,
.decode = decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
More information about the ffmpeg-cvslog
mailing list