@@ -141,19 +141,19 @@ static inline void ls_encode_run(JLSState *state, PutBitContext *pb, int run,
* Encode one line of image
*/
static inline void ls_encode_line(JLSState *state, PutBitContext *pb,
- void *last, void *cur, const void *in, int last2, int w,
+ void *tmp, const void *in, int last2, int w,
int stride, int comp, int bits)
{
int x = 0;
- int Ra = R(last, 0), Rb, Rc = last2, Rd;
+ int Ra = R(tmp, 0), Rb, Rc = last2, Rd;
int D0, D1, D2;
while (x < w) {
int err, pred, sign;
/* compute gradients */
- Rb = R(last, x);
- Rd = (x >= w - stride) ? R(last, x) : R(last, x + stride);
+ Rb = R(tmp, x);
+ Rd = (x >= w - stride) ? R(tmp, x) : R(tmp, x + stride);
D0 = Rd - Rb;
D1 = Rb - Rc;
D2 = Rc - Ra;
@@ -168,13 +168,13 @@ static inline void ls_encode_line(JLSState *state, PutBitContext *pb,
RUNval = Ra;
while (x < w && (FFABS(R(in, x) - RUNval) <= state->near)) {
run++;
- W(cur, x, Ra);
+ W(tmp, x, Ra);
x += stride;
}
ls_encode_run(state, pb, run, comp, x < w);
if (x >= w)
return;
- Rb = R(last, x);
+ Rb = R(tmp, x);
RItype = FFABS(Ra - Rb) <= state->near;
pred = RItype ? Ra : Rb;
err = R(in, x) - pred;
@@ -194,7 +194,7 @@ static inline void ls_encode_line(JLSState *state, PutBitContext *pb,
Ra = av_clip(pred - err * state->twonear, 0, state->maxval);
} else
Ra = R(in, x);
- W(cur, x, Ra);
+ W(tmp, x, Ra);
if (err < 0)
err += state->range;
@@ -236,7 +236,7 @@ static inline void ls_encode_line(JLSState *state, PutBitContext *pb,
Ra = av_clip(pred - err * state->twonear, 0, state->maxval);
} else
Ra = R(in, x);
- W(cur, x, Ra);
+ W(tmp, x, Ra);
ls_encode_regular(state, pb, context, err);
}
@@ -277,9 +277,8 @@ static int encode_picture_ls(AVCodecContext *avctx, AVPacket *pkt,
PutBitContext pb2;
GetBitContext gb;
uint8_t *buf2 = NULL;
- uint8_t *zero = NULL;
const uint8_t *in;
- uint8_t *last, *cur;
+ uint8_t *last = NULL;
JLSState *state = NULL;
int i, size, ret;
int comps;
@@ -345,28 +344,27 @@ FF_ENABLE_DEPRECATION_WARNINGS
ls_store_lse(state, &pb);
- zero = last = av_calloc(FFABS(p->linesize[0]), 2);
- if (!zero)
+ last = av_mallocz(FFABS(p->linesize[0]));
+ if (!last)
goto memfail;
- cur = zero + FFABS(p->linesize[0]);
in = p->data[0];
if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
int t = 0;
for (i = 0; i < avctx->height; i++) {
- ls_encode_line(state, &pb2, last, cur, in, t, avctx->width, 1, 0, 8);
- t = last[0];
- FFSWAP(void *, last, cur);
+ int last0 = last[0];
+ ls_encode_line(state, &pb2, last, in, t, avctx->width, 1, 0, 8);
+ t = last0;
in += p->linesize[0];
}
} else if (avctx->pix_fmt == AV_PIX_FMT_GRAY16) {
int t = 0;
for (i = 0; i < avctx->height; i++) {
- ls_encode_line(state, &pb2, last, cur, in, t, avctx->width, 1, 0, 16);
- t = *((uint16_t *)last);
- FFSWAP(void *, last, cur);
+ int last0 = *((uint16_t *)last);
+ ls_encode_line(state, &pb2, last, in, t, avctx->width, 1, 0, 16);
+ t = last0;
in += p->linesize[0];
}
} else if (avctx->pix_fmt == AV_PIX_FMT_RGB24) {
@@ -376,11 +374,11 @@ FF_ENABLE_DEPRECATION_WARNINGS
width = avctx->width * 3;
for (i = 0; i < avctx->height; i++) {
for (j = 0; j < 3; j++) {
- ls_encode_line(state, &pb2, last + j, cur + j, in + j, Rc[j],
+ int last0 = last[j];
+ ls_encode_line(state, &pb2, last + j, in + j, Rc[j],
width, 3, j, 8);
- Rc[j] = last[j];
+ Rc[j] = last0;
}
- FFSWAP(void *, last, cur);
in += p->linesize[0];
}
} else if (avctx->pix_fmt == AV_PIX_FMT_BGR24) {
@@ -390,16 +388,16 @@ FF_ENABLE_DEPRECATION_WARNINGS
width = avctx->width * 3;
for (i = 0; i < avctx->height; i++) {
for (j = 2; j >= 0; j--) {
- ls_encode_line(state, &pb2, last + j, cur + j, in + j, Rc[j],
+ int last0 = last[j];
+ ls_encode_line(state, &pb2, last + j, in + j, Rc[j],
width, 3, j, 8);
- Rc[j] = last[j];
+ Rc[j] = last0;
}
- FFSWAP(void *, last, cur);
in += p->linesize[0];
}
}
- av_freep(&zero);
+ av_freep(&last);
av_freep(&state);
/* the specification says that after doing 0xff escaping unused bits in
@@ -436,7 +434,7 @@ memfail:
av_packet_unref(pkt);
av_freep(&buf2);
av_freep(&state);
- av_freep(&zero);
+ av_freep(&last);
return AVERROR(ENOMEM);
}
ls_encode_line() encodes one line of input from left to right and to do so it uses the values of the left, upper left, upper and upper right pixels for prediction (i.e. the values that a decoder gets when it decodes the already encoded part of the picture). So a simple algorithm would use a buffer that can hold two lines, namely the current line as well as the last line and swap the pointers to the two lines after decoding each line. Yet if one is currently encoding the pixel with index k of a line, one doesn't need any pixel with index < k - 1 of the last line at all and similarly, no pixels with index >= k have been written yet. So the overlap in the effective lifetime is pretty limited and since the last patch (which stopped reading the upper left pixel and instead reused the value of the upper pixel from the last iteration of the loop) it is inexistent. Ergo one only needs one line and doesn't need to swap the lines out. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> --- libavcodec/jpeglsenc.c | 52 ++++++++++++++++++++---------------------- 1 file changed, 25 insertions(+), 27 deletions(-)