/*
* Copyright (c) 2003-2013 Loren Merritt
* Copyright (c) 2015 Paul B Mahol
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/* Computes the Structural Similarity Metric between two video streams.
* original algorithm:
* Z. Wang, A. C. Bovik, H. R. Sheikh and E. P. Simoncelli,
* "Image quality assessment: From error visibility to structural similarity,"
* IEEE Transactions on Image Processing, vol. 13, no. 4, pp. 600-612, Apr. 2004.
*
* To improve speed, this implementation uses the standard approximation of
* overlapped 8x8 block sums, rather than the original gaussian weights.
*/
/*
* @file
* Caculate the SSIM between two input videos.
*/
#include "libavutil/avstring.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "avfilter.h"
#include "dualinput.h"
#include "drawutils.h"
#include "formats.h"
#include "internal.h"
#include "ssim.h"
#include "video.h"
typedef struct SSIMContext {
const AVClass *class;
FFDualInputContext dinput;
FILE *stats_file;
char *stats_file_str;
int nb_components;
uint64_t nb_frames;
double ssim[4], ssim_total;
char comps[4];
float coefs[4];
uint8_t rgba_map[4];
int planewidth[4];
int planeheight[4];
int *temp;
int is_rgb;
SSIMDSPContext dsp;
} SSIMContext;
#define OFFSET(x) offsetof(SSIMContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
static const AVOption ssim_options[] = {
{"stats_file", "Set file where to store per-frame difference information", OFFSET(stats_file_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
{"f", "Set file where to store per-frame difference information", OFFSET(stats_file_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(ssim);
static void set_meta(AVDictionary **metadata, const char *key, char comp, float d)
{
char value[128];
snprintf(value
, sizeof(value
), "%0.2f", d
); if (comp) {
char key2[128];
snprintf(key2
, sizeof(key2
), "%s%c", key
, comp
); av_dict_set(metadata, key2, value, 0);
} else {
av_dict_set(metadata, key, value, 0);
}
}
static void ssim_4x4xn(const uint8_t *main, ptrdiff_t main_stride,
const uint8_t *ref, ptrdiff_t ref_stride,
int (*sums)[4], int width)
{
int x, y, z;
for (z = 0; z < width; z++) {
uint32_t s1 = 0, s2 = 0, ss = 0, s12 = 0;
for (y = 0; y < 4; y++) {
for (x = 0; x < 4; x++) {
int a = main[x + y * main_stride];
int b = ref[x + y * ref_stride];
s1 += a;
s2 += b;
ss += a*a;
ss += b*b;
s12 += a*b;
}
}
sums[z][0] = s1;
sums[z][1] = s2;
sums[z][2] = ss;
sums[z][3] = s12;
main += 4;
ref += 4;
}
}
static float ssim_end1(int s1, int s2, int ss, int s12)
{
static const int ssim_c1 = (int)(.01*.01*255*255*64 + .5);
static const int ssim_c2 = (int)(.03*.03*255*255*64*63 + .5);
int fs1 = s1;
int fs2 = s2;
int fss = ss;
int fs12 = s12;
int vars = fss * 64 - fs1 * fs1 - fs2 * fs2;
int covar = fs12 * 64 - fs1 * fs2;
return (float)(2 * fs1 * fs2 + ssim_c1) * (float)(2 * covar + ssim_c2)
/ ((float)(fs1 * fs1 + fs2 * fs2 + ssim_c1) * (float)(vars + ssim_c2));
}
static float ssim_endn(const int (*sum0)[4], const int (*sum1)[4], int width)
{
float ssim = 0.0;
int i;
for (i = 0; i < width; i++)
ssim += ssim_end1(sum0[i][0] + sum0[i + 1][0] + sum1[i][0] + sum1[i + 1][0],
sum0[i][1] + sum0[i + 1][1] + sum1[i][1] + sum1[i + 1][1],
sum0[i][2] + sum0[i + 1][2] + sum1[i][2] + sum1[i + 1][2],
sum0[i][3] + sum0[i + 1][3] + sum1[i][3] + sum1[i + 1][3]);
return ssim;
}
static float ssim_plane(SSIMDSPContext *dsp,
uint8_t *main, int main_stride,
uint8_t *ref, int ref_stride,
int width, int height, void *temp)
{
int z = 0, y;
float ssim = 0.0;
int (*sum0)[4] = temp;
int (*sum1)[4] = sum0 + (width >> 2) + 3;
width >>= 2;
height >>= 2;
for (y = 1; y < height; y++) {
for (; z <= y; z++) {
FFSWAP(void*, sum0, sum1);
dsp->ssim_4x4_line(&main[4 * z * main_stride], main_stride,
&ref[4 * z * ref_stride], ref_stride,
sum0, width);
}
ssim += dsp->ssim_end_line((const int (*)[4])sum0, (const int (*)[4])sum1, width - 1);
}
return ssim / ((height - 1) * (width - 1));
}
static double ssim_db(double ssim, double weight)
{
return 10 * (log(weight
) / log(10) - log(weight
- ssim
) / log(10)); }
static AVFrame *do_ssim(AVFilterContext *ctx, AVFrame *main,
const AVFrame *ref)
{
AVDictionary **metadata = avpriv_frame_get_metadatap(main);
SSIMContext *s = ctx->priv;
float c[4], ssimv = 0.0;
int i;
s->nb_frames++;
for (i = 0; i < s->nb_components; i++) {
c[i] = ssim_plane(&s->dsp, main->data[i], main->linesize[i],
ref->data[i], ref->linesize[i],
s->planewidth[i], s->planeheight[i], s->temp);
ssimv += s->coefs[i] * c[i];
s->ssim[i] += c[i];
}
for (i = 0; i < s->nb_components; i++) {
int cidx = s->is_rgb ? s->rgba_map[i] : i;
set_meta(metadata, "lavfi.ssim.", s->comps[i], c[cidx]);
}
s->ssim_total += ssimv;
set_meta(metadata, "lavfi.ssim.All", 0, ssimv);
set_meta(metadata, "lavfi.ssim.dB", 0, ssim_db(ssimv, 1.0));
if (s->stats_file) {
fprintf(s
->stats_file
, "n:%"PRId64
" ", s
->nb_frames
);
for (i = 0; i < s->nb_components; i++) {
int cidx = s->is_rgb ? s->rgba_map[i] : i;
fprintf(s
->stats_file
, "%c:%f ", s
->comps
[i
], c
[cidx
]); }
fprintf(s
->stats_file
, "All:%f (%f)\n", ssimv
, ssim_db
(ssimv
, 1.0)); }
return main;
}
static av_cold int init(AVFilterContext *ctx)
{
SSIMContext *s = ctx->priv;
if (s->stats_file_str) {
s
->stats_file
= fopen(s
->stats_file_str
, "w"); if (!s->stats_file) {
int err = AVERROR(errno);
char buf[128];
av_strerror(err, buf, sizeof(buf));
av_log(ctx, AV_LOG_ERROR, "Could not open stats file %s: %s\n",
s->stats_file_str, buf);
return err;
}
}
s->dinput.process = do_ssim;
s->dinput.shortest = 1;
s->dinput.repeatlast = 0;
return 0;
}
static int query_formats(AVFilterContext *ctx)
{
static const enum AVPixelFormat pix_fmts[] = {
AV_PIX_FMT_GRAY8,
AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P,
AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
AV_PIX_FMT_GBRP,
AV_PIX_FMT_NONE
};
AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
if (!fmts_list)
return AVERROR(ENOMEM);
return ff_set_common_formats(ctx, fmts_list);
}
static int config_input_ref(AVFilterLink *inlink)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
AVFilterContext *ctx = inlink->dst;
SSIMContext *s = ctx->priv;
int sum = 0, i;
s->nb_components = desc->nb_components;
if (ctx->inputs[0]->w != ctx->inputs[1]->w ||
ctx->inputs[0]->h != ctx->inputs[1]->h) {
av_log(ctx, AV_LOG_ERROR, "Width and height of input videos must be same.\n");
return AVERROR(EINVAL);
}
if (ctx->inputs[0]->format != ctx->inputs[1]->format) {
av_log(ctx, AV_LOG_ERROR, "Inputs must be of same pixel format.\n");
return AVERROR(EINVAL);
}
s->is_rgb = ff_fill_rgba_map(s->rgba_map, inlink->format) >= 0;
s->comps[0] = s->is_rgb ? 'R' : 'Y';
s->comps[1] = s->is_rgb ? 'G' : 'U';
s->comps[2] = s->is_rgb ? 'B' : 'V';
s->comps[3] = 'A';
s->planeheight[1] = s->planeheight[2] = FF_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
s->planeheight[0] = s->planeheight[3] = inlink->h;
s->planewidth[1] = s->planewidth[2] = FF_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
s->planewidth[0] = s->planewidth[3] = inlink->w;
for (i = 0; i < s->nb_components; i++)
sum += s->planeheight[i] * s->planewidth[i];
for (i = 0; i < s->nb_components; i++)
s->coefs[i] = (double) s->planeheight[i] * s->planewidth[i] / sum;
s->temp = av_malloc((2 * inlink->w + 12) * sizeof(*s->temp));
if (!s->temp)
return AVERROR(ENOMEM);
s->dsp.ssim_4x4_line = ssim_4x4xn;
s->dsp.ssim_end_line = ssim_endn;
if (ARCH_X86)
ff_ssim_init_x86(&s->dsp);
return 0;
}
static int config_output(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
SSIMContext *s = ctx->priv;
AVFilterLink *mainlink = ctx->inputs[0];
int ret;
outlink->w = mainlink->w;
outlink->h = mainlink->h;
outlink->time_base = mainlink->time_base;
outlink->sample_aspect_ratio = mainlink->sample_aspect_ratio;
outlink->frame_rate = mainlink->frame_rate;
if ((ret = ff_dualinput_init(ctx, &s->dinput)) < 0)
return ret;
return 0;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
{
SSIMContext *s = inlink->dst->priv;
return ff_dualinput_filter_frame(&s->dinput, inlink, buf);
}
static int request_frame(AVFilterLink *outlink)
{
SSIMContext *s = outlink->src->priv;
return ff_dualinput_request_frame(&s->dinput, outlink);
}
static av_cold void uninit(AVFilterContext *ctx)
{
SSIMContext *s = ctx->priv;
if (s->nb_frames > 0) {
char buf[256];
int i;
buf[0] = 0;
for (i = 0; i < s->nb_components; i++) {
int c = s->is_rgb ? s->rgba_map[i] : i;
av_strlcatf(buf, sizeof(buf), " %c:%f", s->comps[i], s->ssim[c] / s->nb_frames);
}
av_log(ctx, AV_LOG_INFO, "SSIM%s All:%f (%f)\n", buf,
s->ssim_total / s->nb_frames, ssim_db(s->ssim_total, s->nb_frames));
}
ff_dualinput_uninit(&s->dinput);
if (s->stats_file)
av_freep(&s->temp);
}
static const AVFilterPad ssim_inputs[] = {
{
.name = "main",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
},{
.name = "reference",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
.config_props = config_input_ref,
},
{ NULL }
};
static const AVFilterPad ssim_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_output,
.request_frame = request_frame,
},
{ NULL }
};
AVFilter ff_vf_ssim = {
.name = "ssim",
.description = NULL_IF_CONFIG_SMALL("Calculate the SSIM between two video streams."),
.init = init,
.uninit = uninit,
.query_formats = query_formats,
.priv_size = sizeof(SSIMContext),
.priv_class = &ssim_class,
.inputs = ssim_inputs,
.outputs = ssim_outputs,
};