[FFmpeg-devel] OpenExr Compression technique added -GSoc 15
greeshma
greeshmabalabadra at gmail.com
Tue Mar 24 08:07:08 CET 2015
Got it corrected,New patch
The code is based on Openexr.
Author: greeshmab <greeshmabalabadra at gmail.com> 2015-03-24 12:36:21
Committer: greeshmab <greeshmabalabadra at gmail.com> 2015-03-24 12:36:21
Parent: 4c54709b600ff6a92377ab3e2d5fa33b31970288 (A new EXR lossy
compression technique B44 is added)
Branch: temp
Follows: n2.6-dev
Precedes:
A new exr lossy compression technique B44 is added
------------------------------- libavcodec/exr.c
-------------------------------
index 6251fb7..b7114be 100644
@@ -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:
Greeshma Balabhadra
Pre final Undergraduate
IIT Guwahati
+91 7896366744
greeshma at iitg.ernet.in
On Sun, Mar 22, 2015 at 4:52 AM, Michael Niedermayer <michaelni at gmx.at>
wrote:
> On Sun, Mar 22, 2015 at 01:12:57AM +0530, greeshma wrote:
> > New compression technique -B44 lossy compression for OpenExr
> >
> > From d6da9dea16a5b8247aac60a0ce21cb56981e66ec Mon Sep 17 00:00:00 2001
> > From: greeshmab <greeshmabalabadra at gmail.com>
> > Date: Sun, 22 Mar 2015 01:09:53 +0530
> > Subject: [PATCH] new compression
> >
> [...]
> > exr.c | 122
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 122 insertions(+)
> > 3a408b9625437f474632f0f9247f3bf5a86e6323 0001-new-compression.patch
> > From d6da9dea16a5b8247aac60a0ce21cb56981e66ec Mon Sep 17 00:00:00 2001
> > From: greeshmab <greeshmabalabadra at gmail.com>
> > Date: Sun, 22 Mar 2015 01:09:53 +0530
>
> > Subject: [PATCH] new compression
>
> the commit message is too unclear/unspecific. it should explain what
> is added and why
> also it should mention where code is from if its based on some
> previously existing code
>
>
> >
> > ---
> > libavcodec/exr.c | 122
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 122 insertions(+)
>
> this breaks
> make fate-exr
>
> TEST exr-slice-raw
> TEST exr-slice-rle
> TEST exr-slice-zip1
> TEST exr-slice-zip16
> TEST exr-slice-pxr24
> --- ./tests/ref/fate/exr-slice-rle 2015-03-21 12:36:23.469794458 +0100
> +++ tests/data/fate/exr-slice-rle 2015-03-22 00:17:20.670680485 +0100
> @@ -1,2 +1,2 @@
> #tb 0: 1/25
> -0, 0, 0, 1, 3169800, 0x6a356d0d
> +0, 0, 0, 1, 3169800, 0x00000000
> Test exr-slice-rle failed. Look at tests/data/fate/exr-slice-rle.err for
> details.
> make: *** [fate-exr-slice-rle] Error 1
> make: *** Waiting for unfinished jobs....
>
> you will need the fate samples to run the fate tests see
> https://ffmpeg.org/fate.html#Using-FATE-from-your-FFmpeg-source-directory
>
>
> [...]
>
> --
> Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> Let us carefully observe those good qualities wherein our enemies excel us
> and endeavor to excel them, by avoiding what is faulty, and imitating what
> is excellent in them. -- Plutarch
>
> _______________________________________________
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> ffmpeg-devel at ffmpeg.org
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>
>
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