Go to the documentation of this file.
   34 #define OFFSET(x) offsetof(RemoveGrainContext, x) 
   35 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM 
   66 #define REMOVE_GRAIN_SORT_AXIS       \ 
   67     const int ma1 = FFMAX(a1, a8);   \ 
   68     const int mi1 = FFMIN(a1, a8);   \ 
   69     const int ma2 = FFMAX(a2, a7);   \ 
   70     const int mi2 = FFMIN(a2, a7);   \ 
   71     const int ma3 = FFMAX(a3, a6);   \ 
   72     const int mi3 = FFMIN(a3, a6);   \ 
   73     const int ma4 = FFMAX(a4, a5);   \ 
   74     const int mi4 = FFMIN(a4, a5); 
   84 static int cmp_int(
const void *p1, 
const void *p2)
 
   86     int left  = *(
const int *)p1;
 
   87     int right = *(
const int *)p2;
 
  132     } 
else if (mindiff == 
c2) {
 
  134     } 
else if (mindiff == c3) {
 
  145     const int d1 = ma1 - mi1;
 
  146     const int d2 = ma2 - mi2;
 
  147     const int d3 = ma3 - mi3;
 
  148     const int d4 = ma4 - mi4;
 
  150     const int cli1 = 
av_clip(
c, mi1, ma1);
 
  151     const int cli2 = 
av_clip(
c, mi2, ma2);
 
  152     const int cli3 = 
av_clip(
c, mi3, ma3);
 
  153     const int cli4 = 
av_clip(
c, mi4, ma4);
 
  164     } 
else if (mindiff == 
c2) {
 
  166     } 
else if (mindiff == c3) {
 
  177     const int d1 = ma1 - mi1;
 
  178     const int d2 = ma2 - mi2;
 
  179     const int d3 = ma3 - mi3;
 
  180     const int d4 = ma4 - mi4;
 
  182     const int cli1 = 
av_clip(
c, mi1, ma1);
 
  183     const int cli2 = 
av_clip(
c, mi2, ma2);
 
  184     const int cli3 = 
av_clip(
c, mi3, ma3);
 
  185     const int cli4 = 
av_clip(
c, mi4, ma4);
 
  187     const int c1 = 
FFABS(
c - cli1) + d1;
 
  188     const int c2 = 
FFABS(
c - cli2) + d2;
 
  189     const int c3 = 
FFABS(
c - cli3) + d3;
 
  190     const int c4 = 
FFABS(
c - cli4) + d4;
 
  196     } 
else if (mindiff == 
c2) {
 
  198     } 
else if (mindiff == c3) {
 
  209     const int d1 = ma1 - mi1;
 
  210     const int d2 = ma2 - mi2;
 
  211     const int d3 = ma3 - mi3;
 
  212     const int d4 = ma4 - mi4;
 
  214     const int cli1 = 
av_clip(
c, mi1, ma1);
 
  215     const int cli2 = 
av_clip(
c, mi2, ma2);
 
  216     const int cli3 = 
av_clip(
c, mi3, ma3);
 
  217     const int cli4 = 
av_clip(
c, mi4, ma4);
 
  228     } 
else if (mindiff == 
c2) {
 
  230     } 
else if (mindiff == c3) {
 
  241     const int d1 = ma1 - mi1;
 
  242     const int d2 = ma2 - mi2;
 
  243     const int d3 = ma3 - mi3;
 
  244     const int d4 = ma4 - mi4;
 
  250     } 
else if (mindiff == d2) {
 
  252     } 
else if (mindiff == d3) {
 
  266     const int d6 = 
FFABS(
c - a6);
 
  267     const int d7 = 
FFABS(
c - a7);
 
  268     const int d8 = 
FFABS(
c - a8);
 
  273     if (mindiff == d7) 
return a7;
 
  274     if (mindiff == d8) 
return a8;
 
  275     if (mindiff == d6) 
return a6;
 
  276     if (mindiff == d2) 
return a2;
 
  277     if (mindiff == d3) 
return a3;
 
  278     if (mindiff == d1) 
return a1;
 
  279     if (mindiff == d5) 
return a5;
 
  286     const int sum = 4 * 
c + 2 * (
a2 + 
a4 + 
a5 + a7) + 
a1 + 
a3 + a6 + a8;
 
  287     const int val = (sum + 8) >> 4;
 
  301         return (
a2 + a7 + 1) >> 1;
 
  304         return (
a3 + a6 + 1) >> 1;
 
  307     return (
a1 + a8 + 1) >> 1;
 
  317     const int average = (2 * (
a2 + a7) + 
a1 + 
a3 + a6 + a8 + 4) >> 3;
 
  363     const int sum = 
a1 + 
a2 + 
a3 + 
a4 + 
a5 + a6 + a7 + a8;
 
  364     const int val = (sum + 4) >> 3;
 
  371     const int sum = 
a1 + 
a2 + 
a3 + 
a4 + 
c + 
a5 + a6 + a7 + a8;
 
  372     const int val = (sum + 4) / 9;
 
  379     const int l1l = (
a1 + a8) >> 1;
 
  380     const int l2l = (
a2 + a7) >> 1;
 
  381     const int l3l = (
a3 + a6) >> 1;
 
  382     const int l4l = (
a4 + 
a5) >> 1;
 
  384     const int l1h = (
a1 + a8 + 1) >> 1;
 
  385     const int l2h = (
a2 + a7 + 1) >> 1;
 
  386     const int l3h = (
a3 + a6 + 1) >> 1;
 
  387     const int l4h = (
a4 + 
a5 + 1) >> 1;
 
  397     const int l1 = (
a1 + a8 + 1) >> 1;
 
  398     const int l2 = (
a2 + a7 + 1) >> 1;
 
  399     const int l3 = (
a3 + a6 + 1) >> 1;
 
  400     const int l4 = (
a4 + 
a5 + 1) >> 1;
 
  412     const int linediff1 = ma1 - mi1;
 
  413     const int linediff2 = ma2 - mi2;
 
  414     const int linediff3 = ma3 - mi3;
 
  415     const int linediff4 = ma4 - mi4;
 
  417     const int u1 = 
FFMIN(
c - ma1, linediff1);
 
  418     const int u2 = 
FFMIN(
c - ma2, linediff2);
 
  419     const int u3 = 
FFMIN(
c - ma3, linediff3);
 
  420     const int u4 = 
FFMIN(
c - ma4, linediff4);
 
  423     const int d1 = 
FFMIN(mi1 - 
c, linediff1);
 
  424     const int d2 = 
FFMIN(mi2 - 
c, linediff2);
 
  425     const int d3 = 
FFMIN(mi3 - 
c, linediff3);
 
  426     const int d4 = 
FFMIN(mi4 - 
c, linediff4);
 
  436     const int linediff1 = ma1 - mi1;
 
  437     const int linediff2 = ma2 - mi2;
 
  438     const int linediff3 = ma3 - mi3;
 
  439     const int linediff4 = ma4 - mi4;
 
  441     const int tu1 = 
c - ma1;
 
  442     const int tu2 = 
c - ma2;
 
  443     const int tu3 = 
c - ma3;
 
  444     const int tu4 = 
c - ma4;
 
  446     const int u1 = 
FFMIN(tu1, linediff1 - tu1);
 
  447     const int u2 = 
FFMIN(tu2, linediff2 - tu2);
 
  448     const int u3 = 
FFMIN(tu3, linediff3 - tu3);
 
  449     const int u4 = 
FFMIN(tu4, linediff4 - tu4);
 
  452     const int td1 = mi1 - 
c;
 
  453     const int td2 = mi2 - 
c;
 
  454     const int td3 = mi3 - 
c;
 
  455     const int td4 = mi4 - 
c;
 
  457     const int d1 = 
FFMIN(td1, linediff1 - td1);
 
  458     const int d2 = 
FFMIN(td2, linediff2 - td2);
 
  459     const int d3 = 
FFMIN(td3, linediff3 - td3);
 
  460     const int d4 = 
FFMIN(td4, linediff4 - td4);
 
  475     s->planeheight[0] = 
s->planeheight[3] = 
inlink->h;
 
  477     s->planewidth[0]  = 
s->planewidth[3]  = 
inlink->w;
 
  479     for (
i = 0; 
i < 
s->nb_planes; 
i++) {
 
  480         switch (
s->mode[
i]) {
 
  493         case 13: 
s->skip_odd = 1;
 
  495         case 14: 
s->skip_even = 1;
 
  497         case 15: 
s->skip_odd = 1;
 
  499         case 16: 
s->skip_even = 1;
 
  529     const int i = 
td->plane;
 
  530     const int height = 
s->planeheight[
i];
 
  531     const int om = 
in->linesize[
i] - 1;
 
  532     const int o0 = 
in->linesize[
i]    ;
 
  533     const int op = 
in->linesize[
i] + 1;
 
  534     int start = (
height *  jobnr   ) / nb_jobs;
 
  535     int end   = (
height * (jobnr+1)) / nb_jobs;
 
  538     start = 
FFMAX(1, start);
 
  540     for (y = start; y < end; y++) {
 
  545         dst = 
out->data[
i] + y * 
out->linesize[
i];
 
  547         if (
s->skip_even && !(y & 1)) {
 
  548             memcpy(dst, 
src, 
s->planewidth[
i]);
 
  551         if (
s->skip_odd && y & 1) {
 
  552             memcpy(dst, 
src, 
s->planewidth[
i]);
 
  559             int w_asm = (
s->planewidth[
i] - 2) & ~15;
 
  561             s->fl[
i](dst, 
src, 
in->linesize[
i], w_asm);
 
  569         for (; x < 
s->planewidth[
i] - 1; x++) {
 
  571             const int a2 = 
src[-o0];
 
  572             const int a3 = 
src[-om];
 
  573             const int a4 = 
src[-1 ];
 
  574             const int c  = 
src[ 0 ];
 
  575             const int a5 = 
src[ 1 ];
 
  576             const int a6 = 
src[ om];
 
  577             const int a7 = 
src[ o0];
 
  578             const int a8 = 
src[ 
op];
 
  607     for (
i = 0; 
i < 
s->nb_planes; 
i++) {
 
  611         if (
s->mode[
i] == 0) {
 
  614                                 s->planewidth[
i], 
s->planeheight[
i]);
 
  618         memcpy(dst, 
src, 
s->planewidth[
i]);
 
  624         src = 
in->data[
i] + (
s->planeheight[
i] - 1) * 
in->linesize[
i];
 
  625         dst = 
out->data[
i] + (
s->planeheight[
i] - 1) * 
out->linesize[
i];
 
  626         memcpy(dst, 
src, 
s->planewidth[
i]);
 
  652     .
name          = 
"removegrain",
 
  658     .priv_class    = &removegrain_class,
 
  
AVFrame * ff_get_video_buffer(AVFilterLink *link, int w, int h)
Request a picture buffer with a specific set of permissions.
 
AVPixelFormat
Pixel format.
 
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
 
#define u(width, name, range_min, range_max)
 
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
 
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
 
static int mode19(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
 
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
 
This structure describes decoded (raw) audio or video data.
 
static int mode05(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
void ff_removegrain_init_x86(RemoveGrainContext *rg)
 
@ AV_PIX_FMT_YUV440P
planar YUV 4:4:0 (1 Cr & Cb sample per 1x2 Y samples)
 
static int mode20(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
AVFilter ff_vf_removegrain
 
const char * name
Filter name.
 
static int mode06(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
static int mode18(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
AVFormatInternal * internal
An opaque field for libavformat internal usage.
 
A link between two filters.
 
void av_image_copy_plane(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize, int bytewidth, int height)
Copy image plane from src to dst.
 
static int mode08(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt)
 
AVFILTER_DEFINE_CLASS(removegrain)
 
@ AV_PIX_FMT_GBRAP
planar GBRA 4:4:4:4 32bpp
 
static int mode22(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
static double val(void *priv, double ch)
 
static int mode23(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
A filter pad used for either input or output.
 
static int mode21(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
@ AV_PIX_FMT_YUVJ411P
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples) full scale (JPEG), deprecated in favor ...
 
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 
@ AV_PIX_FMT_YUVJ422P
planar YUV 4:2:2, 16bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV422P and setting col...
 
static const AVFilterPad removegrain_inputs[]
 
@ AV_PIX_FMT_YUVA420P
planar YUV 4:2:0, 20bpp, (1 Cr & Cb sample per 2x2 Y & A samples)
 
static int query_formats(AVFilterContext *ctx)
 
#define AV_CEIL_RSHIFT(a, b)
 
static int mode04(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
static int op(uint8_t **dst, const uint8_t *dst_end, GetByteContext *gb, int pixel, int count, int *x, int width, int linesize)
Perform decode operation.
 
static const AVFilterPad outputs[]
 
static enum AVPixelFormat pix_fmts[]
 
static int mode07(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
static int mode1516(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
 
@ AV_PIX_FMT_YUVJ444P
planar YUV 4:4:4, 24bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV444P and setting col...
 
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
 
int av_frame_copy_props(AVFrame *dst, const AVFrame *src)
Copy only "metadata" fields from src to dst.
 
@ AV_PIX_FMT_YUVJ420P
planar YUV 4:2:0, 12bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV420P and setting col...
 
static int cmp_int(const void *p1, const void *p2)
 
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several inputs
 
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
 
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
 
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
 
#define REMOVE_GRAIN_SORT_AXIS
 
#define FFDIFFSIGN(x, y)
Comparator.
 
static const AVOption removegrain_options[]
 
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
 
@ AV_PIX_FMT_YUVA444P
planar YUV 4:4:4 32bpp, (1 Cr & Cb sample per 1x1 Y & A samples)
 
static int filter_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 
static int mode01(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
#define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
Some filters support a generic "enable" expression option that can be used to enable or disable a fil...
 
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi - 0x80) *(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi - 0x80) *(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(const int16_t *) pi >> 8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t, *(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t, *(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(const int32_t *) pi >> 24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t, *(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t, *(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31)))) #define SET_CONV_FUNC_GROUP(ofmt, ifmt) static void set_generic_function(AudioConvert *ac) { } void ff_audio_convert_free(AudioConvert **ac) { if(! *ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);} AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, int sample_rate, int apply_map) { AudioConvert *ac;int in_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) return NULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method !=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt) > 2) { ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc) { av_free(ac);return NULL;} return ac;} in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar) { ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar ? ac->channels :1;} else if(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;else ac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);return ac;} int ff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in) { int use_generic=1;int len=in->nb_samples;int p;if(ac->dc) { av_log(ac->avr, AV_LOG_TRACE, "%d samples - audio_convert: %s to %s (dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));return ff_convert_dither(ac-> in
 
static int mode24(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
static int config_input(AVFilterLink *inlink)
 
#define AV_QSORT(p, num, type, cmp)
Quicksort This sort is fast, and fully inplace but not stable and it is possible to construct input t...
 
int w
agreed upon image width
 
int ff_filter_get_nb_threads(AVFilterContext *ctx)
Get number of threads for current filter instance.
 
Used for passing data between threads.
 
@ AV_PIX_FMT_YUVJ440P
planar YUV 4:4:0 full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV440P and setting color_range
 
const char * name
Pad name.
 
static int mode02(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
Tag MUST be and< 10hcoeff half pel interpolation filter coefficients, hcoeff[0] are the 2 middle coefficients[1] are the next outer ones and so on, resulting in a filter like:...eff[2], hcoeff[1], hcoeff[0], hcoeff[0], hcoeff[1], hcoeff[2] ... the sign of the coefficients is not explicitly stored but alternates after each coeff and coeff[0] is positive, so ...,+,-,+,-,+,+,-,+,-,+,... hcoeff[0] is not explicitly stored but found by subtracting the sum of all stored coefficients with signs from 32 hcoeff[0]=32 - hcoeff[1] - hcoeff[2] - ... a good choice for hcoeff and htaps is htaps=6 hcoeff={40,-10, 2} an alternative which requires more computations at both encoder and decoder side and may or may not be better is htaps=8 hcoeff={42,-14, 6,-2}ref_frames minimum of the number of available reference frames and max_ref_frames for example the first frame after a key frame always has ref_frames=1spatial_decomposition_type wavelet type 0 is a 9/7 symmetric compact integer wavelet 1 is a 5/3 symmetric compact integer wavelet others are reserved stored as delta from last, last is reset to 0 if always_reset||keyframeqlog quality(logarithmic quantizer scale) stored as delta from last, last is reset to 0 if always_reset||keyframemv_scale stored as delta from last, last is reset to 0 if always_reset||keyframe FIXME check that everything works fine if this changes between framesqbias dequantization bias stored as delta from last, last is reset to 0 if always_reset||keyframeblock_max_depth maximum depth of the block tree stored as delta from last, last is reset to 0 if always_reset||keyframequant_table quantization tableHighlevel bitstream structure:==============================--------------------------------------------|Header|--------------------------------------------|------------------------------------|||Block0||||split?||||yes no||||......... intra?||||:Block01 :yes no||||:Block02 :....... ..........||||:Block03 ::y DC ::ref index:||||:Block04 ::cb DC ::motion x :||||......... :cr DC ::motion y :||||....... ..........|||------------------------------------||------------------------------------|||Block1|||...|--------------------------------------------|------------ ------------ ------------|||Y subbands||Cb subbands||Cr subbands||||--- ---||--- ---||--- ---|||||LL0||HL0||||LL0||HL0||||LL0||HL0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||LH0||HH0||||LH0||HH0||||LH0||HH0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HL1||LH1||||HL1||LH1||||HL1||LH1|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HH1||HL2||||HH1||HL2||||HH1||HL2|||||...||...||...|||------------ ------------ ------------|--------------------------------------------Decoding process:=================------------|||Subbands|------------||||------------|Intra DC||||LL0 subband prediction ------------|\ Dequantization ------------------- \||Reference frames|\ IDWT|------- -------|Motion \|||Frame 0||Frame 1||Compensation . OBMC v -------|------- -------|--------------. \------> Frame n output Frame Frame<----------------------------------/|...|------------------- Range Coder:============Binary Range Coder:------------------- The implemented range coder is an adapted version based upon "Range encoding: an algorithm for removing redundancy from a digitised message." by G. N. N. Martin. The symbols encoded by the Snow range coder are bits(0|1). The associated probabilities are not fix but change depending on the symbol mix seen so far. bit seen|new state ---------+----------------------------------------------- 0|256 - state_transition_table[256 - old_state];1|state_transition_table[old_state];state_transition_table={ 0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 190, 191, 192, 194, 194, 195, 196, 197, 198, 199, 200, 201, 202, 202, 204, 205, 206, 207, 208, 209, 209, 210, 211, 212, 213, 215, 215, 216, 217, 218, 219, 220, 220, 222, 223, 224, 225, 226, 227, 227, 229, 229, 230, 231, 232, 234, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 248, 0, 0, 0, 0, 0, 0, 0};FIXME Range Coding of integers:------------------------- FIXME Neighboring Blocks:===================left and top are set to the respective blocks unless they are outside of the image in which case they are set to the Null block top-left is set to the top left block unless it is outside of the image in which case it is set to the left block if this block has no larger parent block or it is at the left side of its parent block and the top right block is not outside of the image then the top right block is used for top-right else the top-left block is used Null block y, cb, cr are 128 level, ref, mx and my are 0 Motion Vector Prediction:=========================1. the motion vectors of all the neighboring blocks are scaled to compensate for the difference of reference frames scaled_mv=(mv *(256 *(current_reference+1)/(mv.reference+1))+128)> the median of the scaled left
 
static const AVFilterPad removegrain_outputs[]
 
static int mode1112(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
static int mode1314(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
int h
agreed upon image height
 
static int mode03(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
@ AV_PIX_FMT_YUV444P
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
 
static int mode09(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
@ AV_PIX_FMT_GBRP
planar GBR 4:4:4 24bpp
 
#define AVFILTER_FLAG_SLICE_THREADS
The filter supports multithreading by splitting frames into multiple parts and processing them concur...
 
@ AV_PIX_FMT_YUV422P
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
 
static int mode17(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)
 
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
 
@ AV_PIX_FMT_YUV411P
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples)
 
#define flags(name, subs,...)
 
@ AV_PIX_FMT_YUV410P
planar YUV 4:1:0, 9bpp, (1 Cr & Cb sample per 4x4 Y samples)
 
@ AV_PIX_FMT_YUVA422P
planar YUV 4:2:2 24bpp, (1 Cr & Cb sample per 2x1 Y & A samples)
 
static int mode10(int c, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8)