Greeshma
On Wed, Mar 25, 2015 at 10:32 PM, Michael Niedermayer <michae...@gmx.at>
wrote:
> On Tue, Mar 24, 2015 at 04:07:01PM +0530, greeshma wrote:
> > The patch is made and FATE tests are done.It accepted, will submit with
> the
> > copyrights and signature.The code is written based on openEXR algorithm
> of
> > B44 lossy compression and modified according to the FFmpeg code.
> >
> >
> > From 9670e283f38b71c06457c976f3f2040c8d38bbd9 Mon Sep 17 00:00:00 2001
> > From: greeshmab <greeshmabalaba...@gmail.com>
> > Date: Tue, 24 Mar 2015 12:36:21 +0530
> > Subject: [PATCH] A new exr lossy compression technique B44 is added
> >
> > ---
> > libavcodec/exr.c | 121
> > +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 121 insertions(+)
> >
> > diff --git a/libavcodec/exr.c b/libavcodec/exr.c
> > index 6251fb7..b7114be 100644
> > --- a/libavcodec/exr.c
> > +++ b/libavcodec/exr.c
> > @@ -770,6 +770,124 @@ static int piz_uncompress(EXRContext *s, const
> > uint8_t *src, int ssize,
> > return 0;
> > }
> >
> > +
> > +static void B44_unpack14 ( GetByteContext *gb, uint16_t out[16]){
> > + uint16_t shift;
> > + const uint8_t *r = gb->buffer;
> > + av_assert0(r[2] != 0xfc);
> > + out[0] = (r[0] << 8) | r[1];
> > + shift = (r[2] >> 2);
> > + out[ 1] = out[ 0] + ((r[ 5] >> 2) << shift);
> > + out[ 2] = out[ 1] + ((r[ 8] >> 2) << shift);
> > + out[ 3] = out[ 2] + ((r[11] >> 2) << shift);
> > + out[ 4] = out[ 0] + (((r[ 2] << 4) | (r[ 3] >> 4)) << shift);
> > + out[ 5] = out[ 4] + (((r[ 5] << 4) | (r[ 6] >> 4)) << shift);
> > + out[ 6] = out[ 5] + (((r[ 8] << 4) | (r[ 9] >> 4)) << shift);
> > + out[ 7] = out[ 6] + (((r[11] << 4) | (r[12] >> 4)) << shift);
> > + out[ 8] = out[ 4] + (((r[ 3] << 2) | (r[ 4] >> 6)) << shift);
> > + out[ 9] = out[ 8] + (((r[ 6] << 2) | (r[ 7] >> 6)) << shift);
> > + out[10] = out[ 9] + (((r[ 9] << 2) | (r[10] >> 6)) << shift);
> > + out[11] = out[10] + (((r[12] << 2) | (r[13] >> 6)) << shift);
> > + out[12] = out[ 8] + (r[ 4] << shift);
> > + out[13] = out[12] + (r[ 7] << shift);
> > + out[14] = out[13] + (r[10] << shift);
> > + out[15] = out[14] + (r[13] << shift);
> > + for (int i = 0; i < 16; ++i) { //if any out value
> exceeds
> > 16bits
> > + if (out[i] & 0x8000)
>
> the patch is corrupted by linebreaks, please make sure you attach
> the patch if you do not use "git send-email -1"
>
The linebreaks are modified.
>
> also, if the code is based on some other implementtaton this should
> be mentioned in the commit message, you can edit the last commit
> message with git commit --amend
>
> The commit message is changed accordingly
> also it may be needed to add a copyright statement if code has been
> used from elsewhere
>
> The code is not entirely taken from openEXR.I have just used the algorithm
they used to compress and wrote unpack technique accordingly.Does this
require copyright statement for openEXR?
The patch is attached.PFA.
Thanks.
Thanks
>
> [...]
> --
> Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> You can kill me, but you cannot change the truth.
>
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> ffmpeg-devel@ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
>
From 9ab93eb32d4ee7a8cacc5ce98239dd12bc75bf42 Mon Sep 17 00:00:00 2001
From: greeshmab <greeshmabalaba...@gmail.com>
Date: Tue, 24 Mar 2015 12:36:21 +0530
Subject: [PATCH] exr lossy compression B44(based on OpenEXR code)
Signed-off-by: Greeshma <greeshmabalaba...@gmail.com>
---
libavcodec/exr.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 121 insertions(+)
diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index 6251fb7..d184fb9 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -770,6 +770,124 @@ static int piz_uncompress(EXRContext *s, const uint8_t *src, int ssize,
return 0;
}
+
+
+static void B44_unpack14 ( GetByteContext *gb, uint16_t out[16]){
+ uint16_t shift;
+ const uint8_t *r = gb->buffer;
+ av_assert0(r[2] != 0xfc);
+ out[0] = (r[0] << 8) | r[1];
+ shift = (r[2] >> 2);
+ out[ 1] = out[ 0] + ((r[ 5] >> 2) << shift);
+ out[ 2] = out[ 1] + ((r[ 8] >> 2) << shift);
+ out[ 3] = out[ 2] + ((r[11] >> 2) << shift);
+ out[ 4] = out[ 0] + (((r[ 2] << 4) | (r[ 3] >> 4)) << shift);
+ out[ 5] = out[ 4] + (((r[ 5] << 4) | (r[ 6] >> 4)) << shift);
+ out[ 6] = out[ 5] + (((r[ 8] << 4) | (r[ 9] >> 4)) << shift);
+ out[ 7] = out[ 6] + (((r[11] << 4) | (r[12] >> 4)) << shift);
+ out[ 8] = out[ 4] + (((r[ 3] << 2) | (r[ 4] >> 6)) << shift);
+ out[ 9] = out[ 8] + (((r[ 6] << 2) | (r[ 7] >> 6)) << shift);
+ out[10] = out[ 9] + (((r[ 9] << 2) | (r[10] >> 6)) << shift);
+ out[11] = out[10] + (((r[12] << 2) | (r[13] >> 6)) << shift);
+ out[12] = out[ 8] + (r[ 4] << shift);
+ out[13] = out[12] + (r[ 7] << shift);
+ out[14] = out[13] + (r[10] << shift);
+ out[15] = out[14] + (r[13] << shift);
+ for (int i = 0; i < 16; ++i) { //if any out value exceeds 16bits
+ if (out[i] & 0x8000)
+ out[i] &= 0x7fff;
+ else
+ out[i] = ~out[i];
+ }
+}
+
+
+static void B44_unpack3 ( GetByteContext *gb, uint16_t out[16]){
+ const uint8_t *r = gb->buffer; //pixels have the same value
+ av_assert0(r[2] == 0xfc);
+ out[0] = (r[0] << 8) | r[1];
+ if (out[0] & 0x8000)
+ out[0] &= 0x7fff;
+ else
+ out[0] = ~out[0];
+ for (int i = 1; i < 16; ++i)
+ out[i] = out[0];
+}
+
+
+
+static int b44_uncompress(EXRContext *s, const uint8_t *src,int ssize, int dsize, EXRThreadData *td)
+
+{
+ GetByteContext gb;
+ unsigned long dest_len = dsize;
+ uint8_t *out;
+ int i, j;
+ uint16_t *tmp = (uint16_t *)td->tmp;
+ out = td->uncompressed_data;
+ bytestream2_init(&gb, src, ssize);
+ if (uncompress(td->tmp, &dest_len, src, ssize) != Z_OK || dest_len != dsize)
+ return AVERROR_INVALIDDATA;
+ for (i = 0; i < s->nb_channels; i++) {
+ EXRChannel *channel = &s->channels[i];
+ int size = channel->pixel_type;
+ int inSize = ssize;
+ if (channel->pixel_type != EXR_HALF) { // UINT or FLOAT channel.
+ int n = s->xdelta * s->ydelta * size * sizeof (*tmp);
+ memcpy (tmp, gb.buffer, n);
+ gb.buffer += n;
+ inSize -= n;
+ continue;
+ } else { //EXR_HALF Channel
+ for (int y=0; y < s->ydelta; y +=4 ) {
+ uint16_t *row0 = tmp + y * s->xdelta;
+ uint16_t *row1 = row0 + s->xdelta;
+ uint16_t *row2 = row1 + s->xdelta;
+ uint16_t *row3 = row2 + s->xdelta;
+ for (int x = 0; x < s->xdelta; x += 4) {
+ uint16_t out[16];
+ int num = (x + 3 < s->xdelta)? 4 * sizeof (*out) : (s->xdelta - x) * sizeof (*out);
+ if (gb.buffer[2] == 0xfc) {
+ B44_unpack3 (&gb, out);
+ gb.buffer += 3;
+ inSize -= 3;
+ } else {
+ B44_unpack14 (&gb, out);
+ gb.buffer += 14;
+ inSize -= 14;
+ }
+ if (y + 3 < s->ydelta) {
+ memcpy (row0, &out[ 0], num);
+ memcpy (row1, &out[ 4], num);
+ memcpy (row2, &out[ 8], num);
+ memcpy (row3, &out[12], num);
+ } else {
+ memcpy (row0, &out[ 0], num);
+ if (y + 1 < s->ydelta)
+ memcpy (row1, &out[ 4], num);
+ if (y + 2 < s->ydelta)
+ memcpy (row2, &out[ 8], num);
+ }
+ row0 += 4;
+ row1 += 4;
+ row2 += 4;
+ row3 += 4;
+ }
+ }
+ }
+ }
+ for (i = 0; i < s->ysize; i++) {
+ for (j = 0; j < s->nb_channels; j++) {
+ uint16_t *in = tmp + j * s->xdelta * s->ysize + i * s->xdelta;
+ memcpy(out, in, s->xdelta * 2);
+ out += s->xdelta * 2;
+ }
+ }
+ return 0;
+}
+
+
static int pxr24_uncompress(EXRContext *s, const uint8_t *src,
int compressed_size, int uncompressed_size,
EXRThreadData *td)
@@ -888,6 +1006,8 @@ static int decode_block(AVCodecContext *avctx, void *tdata,
break;
case EXR_RLE:
ret = rle_uncompress(src, data_size, uncompressed_size, td);
+ case EXR_B44:
+ ret = b44_uncompress(s, src, data_size, uncompressed_size, td);
}
if (ret < 0) {
av_log(avctx, AV_LOG_ERROR, "decode_block() failed.\n");
@@ -1282,6 +1402,7 @@ static int decode_frame(AVCodecContext *avctx, void *data,
s->scan_lines_per_block = 16;
break;
case EXR_PIZ:
+ case EXR_B44:
s->scan_lines_per_block = 32;
break;
default:
--
2.1.4
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