libavfilter/vf_signature.c
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 /*
  * Copyright (c) 2017 Gerion Entrup
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 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 General Public License for more details.
  *
  * You should have received a copy of the GNU 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.
  */
 
 /**
  * @file
  * MPEG-7 video signature calculation and lookup filter
  * @see http://epubs.surrey.ac.uk/531590/1/MPEG-7%20Video%20Signature%20Author%27s%20Copy.pdf
  */
 
 #include <float.h>
 #include "libavcodec/put_bits.h"
 #include "libavformat/avformat.h"
 #include "libavutil/opt.h"
 #include "libavutil/avstring.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/timestamp.h"
 #include "avfilter.h"
 #include "internal.h"
 #include "signature.h"
 #include "signature_lookup.c"
 
 #define OFFSET(x) offsetof(SignatureContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM
 #define BLOCK_LCM (int64_t) 476985600
 
 static const AVOption signature_options[] = {
     { "detectmode", "set the detectmode",
         OFFSET(mode),         AV_OPT_TYPE_INT,    {.i64 = MODE_OFF}, 0, NB_LOOKUP_MODE-1, FLAGS, "mode" },
         { "off",  NULL, 0, AV_OPT_TYPE_CONST, {.i64 = MODE_OFF},  0, 0, .flags = FLAGS, "mode" },
         { "full", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = MODE_FULL}, 0, 0, .flags = FLAGS, "mode" },
         { "fast", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = MODE_FAST}, 0, 0, .flags = FLAGS, "mode" },
     { "nb_inputs",  "number of inputs",
         OFFSET(nb_inputs),    AV_OPT_TYPE_INT,    {.i64 = 1},        1, INT_MAX,          FLAGS },
     { "filename",   "filename for output files",
         OFFSET(filename),     AV_OPT_TYPE_STRING, {.str = ""},       0, NB_FORMATS-1,     FLAGS },
     { "format",     "set output format",
         OFFSET(format),       AV_OPT_TYPE_INT,    {.i64 = FORMAT_BINARY}, 0, 1,           FLAGS , "format" },
         { "binary", 0, 0, AV_OPT_TYPE_CONST, {.i64=FORMAT_BINARY}, 0, 0, FLAGS, "format" },
         { "xml",    0, 0, AV_OPT_TYPE_CONST, {.i64=FORMAT_XML},    0, 0, FLAGS, "format" },
     { "th_d",       "threshold to detect one word as similar",
         OFFSET(thworddist),   AV_OPT_TYPE_INT,    {.i64 = 9000},     1, INT_MAX,          FLAGS },
     { "th_dc",      "threshold to detect all words as similar",
         OFFSET(thcomposdist), AV_OPT_TYPE_INT,    {.i64 = 60000},    1, INT_MAX,          FLAGS },
     { "th_xh",      "threshold to detect frames as similar",
         OFFSET(thl1),         AV_OPT_TYPE_INT,    {.i64 = 116},      1, INT_MAX,          FLAGS },
     { "th_di",      "minimum length of matching sequence in frames",
         OFFSET(thdi),         AV_OPT_TYPE_INT,    {.i64 = 0},        0, INT_MAX,          FLAGS },
     { "th_it",      "threshold for relation of good to all frames",
         OFFSET(thit),         AV_OPT_TYPE_DOUBLE, {.dbl = 0.5},    0.0, 1.0,              FLAGS },
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(signature);
 
 static int query_formats(AVFilterContext *ctx)
 {
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     /* all formats with a separate gray value */
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     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_GRAY8,
         AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P,
         AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P,
         AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P,
         AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUVJ420P,
         AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ444P,
         AV_PIX_FMT_YUVJ440P,
         AV_PIX_FMT_NV12, AV_PIX_FMT_NV21,
         AV_PIX_FMT_NONE
     };
 
     return ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
 }
 
 static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     SignatureContext *sic = ctx->priv;
     StreamContext *sc = &(sic->streamcontexts[FF_INLINK_IDX(inlink)]);
 
     sc->time_base = inlink->time_base;
     /* test for overflow */
     sc->divide = (((uint64_t) inlink->w/32) * (inlink->w/32 + 1) * (inlink->h/32 * inlink->h/32 + 1) > INT64_MAX / (BLOCK_LCM * 255));
     if (sc->divide) {
         av_log(ctx, AV_LOG_WARNING, "Input dimension too high for precise calculation, numbers will be rounded.\n");
     }
     sc->w = inlink->w;
     sc->h = inlink->h;
     return 0;
 }
 
 static int get_block_size(const Block *b)
 {
     return (b->to.y - b->up.y + 1) * (b->to.x - b->up.x + 1);
 }
 
 static uint64_t get_block_sum(StreamContext *sc, uint64_t intpic[32][32], const Block *b)
 {
     uint64_t sum = 0;
 
     int x0, y0, x1, y1;
 
     x0 = b->up.x;
     y0 = b->up.y;
     x1 = b->to.x;
     y1 = b->to.y;
 
     if (x0-1 >= 0 && y0-1 >= 0) {
         sum = intpic[y1][x1] + intpic[y0-1][x0-1] - intpic[y1][x0-1] - intpic[y0-1][x1];
     } else if (x0-1 >= 0) {
         sum = intpic[y1][x1] - intpic[y1][x0-1];
     } else if (y0-1 >= 0) {
         sum = intpic[y1][x1] - intpic[y0-1][x1];
     } else {
         sum = intpic[y1][x1];
     }
     return sum;
 }
 
 static int cmp(const uint64_t *a, const uint64_t *b)
 {
     return *a < *b ? -1 : ( *a > *b ? 1 : 0 );
 }
 
 /**
  * sets the bit at position pos to 1 in data
  */
 static void set_bit(uint8_t* data, size_t pos)
 {
     uint8_t mask = 1 << 7-(pos%8);
     data[pos/8] |= mask;
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
 {
     AVFilterContext *ctx = inlink->dst;
     SignatureContext *sic = ctx->priv;
     StreamContext *sc = &(sic->streamcontexts[FF_INLINK_IDX(inlink)]);
     FineSignature* fs;
 
     static const uint8_t pot3[5] = { 3*3*3*3, 3*3*3, 3*3, 3, 1 };
     /* indexes of words : 210,217,219,274,334  44,175,233,270,273  57,70,103,237,269  100,285,295,337,354  101,102,111,275,296
     s2usw = sorted to unsorted wordvec: 44 is at index 5, 57 at index 10...
     */
     static const unsigned int wordvec[25] = {44,57,70,100,101,102,103,111,175,210,217,219,233,237,269,270,273,274,275,285,295,296,334,337,354};
     static const uint8_t      s2usw[25]   = { 5,10,11, 15, 20, 21, 12, 22,  6,  0,  1,  2,  7, 13, 14,  8,  9,  3, 23, 16, 17, 24,  4, 18, 19};
 
     uint8_t wordt2b[5] = { 0, 0, 0, 0, 0 }; /* word ternary to binary */
     uint64_t intpic[32][32];
     uint64_t rowcount;
     uint8_t *p = picref->data[0];
     int inti, intj;
     int *intjlut;
 
     uint64_t conflist[DIFFELEM_SIZE];
     int f = 0, g = 0, w = 0;
     int32_t dh1 = 1, dh2 = 1, dw1 = 1, dw2 = 1, a, b;
     int64_t denom;
     int i, j, k, ternary;
     uint64_t blocksum;
     int blocksize;
     int64_t th; /* threshold */
     int64_t sum;
 
     int64_t precfactor = (sc->divide) ? 65536 : BLOCK_LCM;
 
     /* initialize fs */
     if (sc->curfinesig) {
         fs = av_mallocz(sizeof(FineSignature));
         if (!fs)
             return AVERROR(ENOMEM);
         sc->curfinesig->next = fs;
         fs->prev = sc->curfinesig;
         sc->curfinesig = fs;
     } else {
         fs = sc->curfinesig = sc->finesiglist;
         sc->curcoarsesig1->first = fs;
     }
 
     fs->pts = picref->pts;
     fs->index = sc->lastindex++;
 
     memset(intpic, 0, sizeof(uint64_t)*32*32);
     intjlut = av_malloc_array(inlink->w, sizeof(int));
     if (!intjlut)
         return AVERROR(ENOMEM);
     for (i = 0; i < inlink->w; i++) {
         intjlut[i] = (i*32)/inlink->w;
     }
 
     for (i = 0; i < inlink->h; i++) {
         inti = (i*32)/inlink->h;
         for (j = 0; j < inlink->w; j++) {
             intj = intjlut[j];
             intpic[inti][intj] += p[j];
         }
         p += picref->linesize[0];
     }
     av_freep(&intjlut);
 
     /* The following calculates a summed area table (intpic) and brings the numbers
      * in intpic to the same denominator.
      * So you only have to handle the numinator in the following sections.
      */
     dh1 = inlink->h / 32;
     if (inlink->h % 32)
         dh2 = dh1 + 1;
     dw1 = inlink->w / 32;
     if (inlink->w % 32)
         dw2 = dw1 + 1;
     denom = (sc->divide) ? dh1 * dh2 * dw1 * dw2 : 1;
 
     for (i = 0; i < 32; i++) {
         rowcount = 0;
         a = 1;
         if (dh2 > 1) {
             a = ((inlink->h*(i+1))%32 == 0) ? (inlink->h*(i+1))/32 - 1 : (inlink->h*(i+1))/32;
             a -= ((inlink->h*i)%32 == 0) ? (inlink->h*i)/32 - 1 : (inlink->h*i)/32;
             a = (a == dh1)? dh2 : dh1;
         }
         for (j = 0; j < 32; j++) {
             b = 1;
             if (dw2 > 1) {
                 b = ((inlink->w*(j+1))%32 == 0) ? (inlink->w*(j+1))/32 - 1 : (inlink->w*(j+1))/32;
                 b -= ((inlink->w*j)%32 == 0) ? (inlink->w*j)/32 - 1 : (inlink->w*j)/32;
                 b = (b == dw1)? dw2 : dw1;
             }
             rowcount += intpic[i][j] * a * b * precfactor / denom;
             if (i > 0) {
                 intpic[i][j] = intpic[i-1][j] + rowcount;
             } else {
                 intpic[i][j] = rowcount;
             }
         }
     }
 
     denom = (sc->divide) ? 1 : dh1 * dh2 * dw1 * dw2;
 
     for (i = 0; i < ELEMENT_COUNT; i++) {
         const ElemCat* elemcat = elements[i];
         int64_t* elemsignature;
         uint64_t* sortsignature;
 
         elemsignature = av_malloc_array(elemcat->elem_count, sizeof(int64_t));
         if (!elemsignature)
             return AVERROR(ENOMEM);
         sortsignature = av_malloc_array(elemcat->elem_count, sizeof(int64_t));
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         if (!sortsignature) {
             av_freep(&elemsignature);
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             return AVERROR(ENOMEM);
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         }
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         for (j = 0; j < elemcat->elem_count; j++) {
             blocksum = 0;
             blocksize = 0;
             for (k = 0; k < elemcat->left_count; k++) {
                 blocksum += get_block_sum(sc, intpic, &elemcat->blocks[j*elemcat->block_count+k]);
                 blocksize += get_block_size(&elemcat->blocks[j*elemcat->block_count+k]);
             }
             sum = blocksum / blocksize;
             if (elemcat->av_elem) {
                 sum -= 128 * precfactor * denom;
             } else {
                 blocksum = 0;
                 blocksize = 0;
                 for (; k < elemcat->block_count; k++) {
                     blocksum += get_block_sum(sc, intpic, &elemcat->blocks[j*elemcat->block_count+k]);
                     blocksize += get_block_size(&elemcat->blocks[j*elemcat->block_count+k]);
                 }
                 sum -= blocksum / blocksize;
                 conflist[g++] = FFABS(sum * 8 / (precfactor * denom));
             }
 
             elemsignature[j] = sum;
             sortsignature[j] = FFABS(sum);
         }
 
         /* get threshold */
         qsort(sortsignature, elemcat->elem_count, sizeof(uint64_t), (void*) cmp);
         th = sortsignature[(int) (elemcat->elem_count*0.333)];
 
         /* ternarize */
         for (j = 0; j < elemcat->elem_count; j++) {
             if (elemsignature[j] < -th) {
                 ternary = 0;
             } else if (elemsignature[j] <= th) {
                 ternary = 1;
             } else {
                 ternary = 2;
             }
             fs->framesig[f/5] += ternary * pot3[f%5];
 
             if (f == wordvec[w]) {
                 fs->words[s2usw[w]/5] += ternary * pot3[wordt2b[s2usw[w]/5]++];
                 if (w < 24)
                     w++;
             }
             f++;
         }
         av_freep(&elemsignature);
         av_freep(&sortsignature);
     }
 
     /* confidence */
     qsort(conflist, DIFFELEM_SIZE, sizeof(uint64_t), (void*) cmp);
     fs->confidence = FFMIN(conflist[DIFFELEM_SIZE/2], 255);
 
     /* coarsesignature */
     if (sc->coarsecount == 0) {
         if (sc->curcoarsesig2) {
             sc->curcoarsesig1 = av_mallocz(sizeof(CoarseSignature));
             if (!sc->curcoarsesig1)
                 return AVERROR(ENOMEM);
             sc->curcoarsesig1->first = fs;
             sc->curcoarsesig2->next = sc->curcoarsesig1;
             sc->coarseend = sc->curcoarsesig1;
         }
     }
     if (sc->coarsecount == 45) {
         sc->midcoarse = 1;
         sc->curcoarsesig2 = av_mallocz(sizeof(CoarseSignature));
         if (!sc->curcoarsesig2)
             return AVERROR(ENOMEM);
         sc->curcoarsesig2->first = fs;
         sc->curcoarsesig1->next = sc->curcoarsesig2;
         sc->coarseend = sc->curcoarsesig2;
     }
     for (i = 0; i < 5; i++) {
         set_bit(sc->curcoarsesig1->data[i], fs->words[i]);
     }
     /* assuming the actual frame is the last */
     sc->curcoarsesig1->last = fs;
     if (sc->midcoarse) {
         for (i = 0; i < 5; i++) {
             set_bit(sc->curcoarsesig2->data[i], fs->words[i]);
         }
         sc->curcoarsesig2->last = fs;
     }
 
     sc->coarsecount = (sc->coarsecount+1)%90;
 
     /* debug printing finesignature */
     if (av_log_get_level() == AV_LOG_DEBUG) {
         av_log(ctx, AV_LOG_DEBUG, "input %d, confidence: %d\n", FF_INLINK_IDX(inlink), fs->confidence);
 
         av_log(ctx, AV_LOG_DEBUG, "words:");
         for (i = 0; i < 5; i++) {
             av_log(ctx, AV_LOG_DEBUG, " %d:", fs->words[i] );
             av_log(ctx, AV_LOG_DEBUG, " %d", fs->words[i] / pot3[0] );
             for (j = 1; j < 5; j++)
                 av_log(ctx, AV_LOG_DEBUG, ",%d", fs->words[i] % pot3[j-1] / pot3[j] );
             av_log(ctx, AV_LOG_DEBUG, ";");
         }
         av_log(ctx, AV_LOG_DEBUG, "\n");
 
         av_log(ctx, AV_LOG_DEBUG, "framesignature:");
         for (i = 0; i < SIGELEM_SIZE/5; i++) {
             av_log(ctx, AV_LOG_DEBUG, " %d", fs->framesig[i] / pot3[0] );
             for (j = 1; j < 5; j++)
                 av_log(ctx, AV_LOG_DEBUG, ",%d", fs->framesig[i] % pot3[j-1] / pot3[j] );
         }
         av_log(ctx, AV_LOG_DEBUG, "\n");
     }
 
     if (FF_INLINK_IDX(inlink) == 0)
         return ff_filter_frame(inlink->dst->outputs[0], picref);
     return 1;
 }
 
 static int xml_export(AVFilterContext *ctx, StreamContext *sc, const char* filename)
 {
     FineSignature* fs;
     CoarseSignature* cs;
     int i, j;
     FILE* f;
     unsigned int pot3[5] = { 3*3*3*3, 3*3*3, 3*3, 3, 1 };
 
     f = fopen(filename, "w");
     if (!f) {
         int err = AVERROR(EINVAL);
         char buf[128];
         av_strerror(err, buf, sizeof(buf));
         av_log(ctx, AV_LOG_ERROR, "cannot open xml file %s: %s\n", filename, buf);
         return err;
     }
 
     /* header */
     fprintf(f, "<?xml version='1.0' encoding='ASCII' ?>\n");
     fprintf(f, "<Mpeg7 xmlns=\"urn:mpeg:mpeg7:schema:2001\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"urn:mpeg:mpeg7:schema:2001 schema/Mpeg7-2001.xsd\">\n");
     fprintf(f, "  <DescriptionUnit xsi:type=\"DescriptorCollectionType\">\n");
     fprintf(f, "    <Descriptor xsi:type=\"VideoSignatureType\">\n");
     fprintf(f, "      <VideoSignatureRegion>\n");
     fprintf(f, "        <VideoSignatureSpatialRegion>\n");
     fprintf(f, "          <Pixel>0 0 </Pixel>\n");
     fprintf(f, "          <Pixel>%d %d </Pixel>\n", sc->w - 1, sc->h - 1);
     fprintf(f, "        </VideoSignatureSpatialRegion>\n");
     fprintf(f, "        <StartFrameOfSpatialRegion>0</StartFrameOfSpatialRegion>\n");
     /* hoping num is 1, other values are vague */
     fprintf(f, "        <MediaTimeUnit>%d</MediaTimeUnit>\n", sc->time_base.den / sc->time_base.num);
     fprintf(f, "        <MediaTimeOfSpatialRegion>\n");
     fprintf(f, "          <StartMediaTimeOfSpatialRegion>0</StartMediaTimeOfSpatialRegion>\n");
     fprintf(f, "          <EndMediaTimeOfSpatialRegion>%" PRIu64 "</EndMediaTimeOfSpatialRegion>\n", sc->coarseend->last->pts);
     fprintf(f, "        </MediaTimeOfSpatialRegion>\n");
 
     /* coarsesignatures */
     for (cs = sc->coarsesiglist; cs; cs = cs->next) {
         fprintf(f, "        <VSVideoSegment>\n");
         fprintf(f, "          <StartFrameOfSegment>%" PRIu32 "</StartFrameOfSegment>\n", cs->first->index);
         fprintf(f, "          <EndFrameOfSegment>%" PRIu32 "</EndFrameOfSegment>\n", cs->last->index);
         fprintf(f, "          <MediaTimeOfSegment>\n");
         fprintf(f, "            <StartMediaTimeOfSegment>%" PRIu64 "</StartMediaTimeOfSegment>\n", cs->first->pts);
         fprintf(f, "            <EndMediaTimeOfSegment>%" PRIu64 "</EndMediaTimeOfSegment>\n", cs->last->pts);
         fprintf(f, "          </MediaTimeOfSegment>\n");
         for (i = 0; i < 5; i++) {
             fprintf(f, "          <BagOfWords>");
             for (j = 0; j < 31; j++) {
                 uint8_t n = cs->data[i][j];
                 if (j < 30) {
                     fprintf(f, "%d  %d  %d  %d  %d  %d  %d  %d  ", (n & 0x80) >> 7,
                                                                    (n & 0x40) >> 6,
                                                                    (n & 0x20) >> 5,
                                                                    (n & 0x10) >> 4,
                                                                    (n & 0x08) >> 3,
                                                                    (n & 0x04) >> 2,
                                                                    (n & 0x02) >> 1,
                                                                    (n & 0x01));
                 } else {
                     /* print only 3 bit in last byte */
                     fprintf(f, "%d  %d  %d ", (n & 0x80) >> 7,
                                               (n & 0x40) >> 6,
                                               (n & 0x20) >> 5);
                 }
             }
             fprintf(f, "</BagOfWords>\n");
         }
         fprintf(f, "        </VSVideoSegment>\n");
     }
 
     /* finesignatures */
     for (fs = sc->finesiglist; fs; fs = fs->next) {
         fprintf(f, "        <VideoFrame>\n");
         fprintf(f, "          <MediaTimeOfFrame>%" PRIu64 "</MediaTimeOfFrame>\n", fs->pts);
         /* confidence */
         fprintf(f, "          <FrameConfidence>%d</FrameConfidence>\n", fs->confidence);
         /* words */
         fprintf(f, "          <Word>");
         for (i = 0; i < 5; i++) {
             fprintf(f, "%d ", fs->words[i]);
             if (i < 4) {
                 fprintf(f, " ");
             }
         }
         fprintf(f, "</Word>\n");
         /* framesignature */
         fprintf(f, "          <FrameSignature>");
         for (i = 0; i< SIGELEM_SIZE/5; i++) {
             if (i > 0) {
                 fprintf(f, " ");
             }
             fprintf(f, "%d ", fs->framesig[i] / pot3[0]);
             for (j = 1; j < 5; j++)
                 fprintf(f, " %d ", fs->framesig[i] % pot3[j-1] / pot3[j] );
         }
         fprintf(f, "</FrameSignature>\n");
         fprintf(f, "        </VideoFrame>\n");
     }
     fprintf(f, "      </VideoSignatureRegion>\n");
     fprintf(f, "    </Descriptor>\n");
     fprintf(f, "  </DescriptionUnit>\n");
     fprintf(f, "</Mpeg7>\n");
 
     fclose(f);
     return 0;
 }
 
 static int binary_export(AVFilterContext *ctx, StreamContext *sc, const char* filename)
 {
     FILE* f;
     FineSignature* fs;
     CoarseSignature* cs;
     uint32_t numofsegments = (sc->lastindex + 44)/45;
     int i, j;
     PutBitContext buf;
     /* buffer + header + coarsesignatures + finesignature */
     int len = (512 + 6 * 32 + 3*16 + 2 +
         numofsegments * (4*32 + 1 + 5*243) +
         sc->lastindex * (2 + 32 + 6*8 + 608)) / 8;
     uint8_t* buffer = av_malloc_array(len, sizeof(uint8_t));
     if (!buffer)
         return AVERROR(ENOMEM);
 
     f = fopen(filename, "wb");
     if (!f) {
         int err = AVERROR(EINVAL);
         char buf[128];
         av_strerror(err, buf, sizeof(buf));
         av_log(ctx, AV_LOG_ERROR, "cannot open file %s: %s\n", filename, buf);
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         av_freep(&buffer);
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         return err;
     }
     init_put_bits(&buf, buffer, len);
 
     put_bits32(&buf, 1); /* NumOfSpatial Regions, only 1 supported */
     put_bits(&buf, 1, 1); /* SpatialLocationFlag, always the whole image */
     put_bits32(&buf, 0); /* PixelX,1 PixelY,1, 0,0 */
     put_bits(&buf, 16, sc->w-1 & 0xFFFF); /* PixelX,2 */
     put_bits(&buf, 16, sc->h-1 & 0xFFFF); /* PixelY,2 */
     put_bits32(&buf, 0); /* StartFrameOfSpatialRegion */
     put_bits32(&buf, sc->lastindex); /* NumOfFrames */
     /* hoping num is 1, other values are vague */
     /* den/num might be greater than 16 bit, so cutting it */
     put_bits(&buf, 16, 0xFFFF & (sc->time_base.den / sc->time_base.num)); /* MediaTimeUnit */
     put_bits(&buf, 1, 1); /* MediaTimeFlagOfSpatialRegion */
     put_bits32(&buf, 0); /* StartMediaTimeOfSpatialRegion */
     put_bits32(&buf, 0xFFFFFFFF & sc->coarseend->last->pts); /* EndMediaTimeOfSpatialRegion */
     put_bits32(&buf, numofsegments); /* NumOfSegments */
     /* coarsesignatures */
     for (cs = sc->coarsesiglist; cs; cs = cs->next) {
         put_bits32(&buf, cs->first->index); /* StartFrameOfSegment */
         put_bits32(&buf, cs->last->index); /* EndFrameOfSegment */
         put_bits(&buf, 1, 1); /* MediaTimeFlagOfSegment */
         put_bits32(&buf, 0xFFFFFFFF & cs->first->pts); /* StartMediaTimeOfSegment */
         put_bits32(&buf, 0xFFFFFFFF & cs->last->pts); /* EndMediaTimeOfSegment */
         for (i = 0; i < 5; i++) {
             /* put 243 bits ( = 7 * 32 + 19 = 8 * 28 + 19) into buffer */
             for (j = 0; j < 30; j++) {
                 put_bits(&buf, 8, cs->data[i][j]);
             }
             put_bits(&buf, 3, cs->data[i][30] >> 5);
         }
     }
     /* finesignatures */
     put_bits(&buf, 1, 0); /* CompressionFlag, only 0 supported */
     for (fs = sc->finesiglist; fs; fs = fs->next) {
         put_bits(&buf, 1, 1); /* MediaTimeFlagOfFrame */
         put_bits32(&buf, 0xFFFFFFFF & fs->pts); /* MediaTimeOfFrame */
         put_bits(&buf, 8, fs->confidence); /* FrameConfidence */
         for (i = 0; i < 5; i++) {
             put_bits(&buf, 8, fs->words[i]); /* Words */
         }
         /* framesignature */
         for (i = 0; i < SIGELEM_SIZE/5; i++) {
             put_bits(&buf, 8, fs->framesig[i]);
         }
     }
 
     avpriv_align_put_bits(&buf);
     flush_put_bits(&buf);
     fwrite(buffer, 1, put_bits_count(&buf)/8, f);
     fclose(f);
     av_freep(&buffer);
     return 0;
 }
 
 static int export(AVFilterContext *ctx, StreamContext *sc, int input)
 {
     SignatureContext* sic = ctx->priv;
     char filename[1024];
 
     if (sic->nb_inputs > 1) {
         /* error already handled */
         av_assert0(av_get_frame_filename(filename, sizeof(filename), sic->filename, input) == 0);
     } else {
         strcpy(filename, sic->filename);
     }
     if (sic->format == FORMAT_XML) {
         return xml_export(ctx, sc, filename);
     } else {
         return binary_export(ctx, sc, filename);
     }
 }
 
 static int request_frame(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     SignatureContext *sic = ctx->priv;
     StreamContext *sc, *sc2;
     MatchingInfo match;
     int i, j, ret;
     int lookup = 1; /* indicates wheather EOF of all files is reached */
 
     /* process all inputs */
     for (i = 0; i < sic->nb_inputs; i++){
         sc = &(sic->streamcontexts[i]);
 
         ret = ff_request_frame(ctx->inputs[i]);
 
         /* return if unexpected error occurs in input stream */
         if (ret < 0 && ret != AVERROR_EOF)
             return ret;
 
         /* export signature at EOF */
         if (ret == AVERROR_EOF && !sc->exported) {
             /* export if wanted */
             if (strlen(sic->filename) > 0) {
                 if (export(ctx, sc, i) < 0)
                     return ret;
             }
             sc->exported = 1;
         }
         lookup &= sc->exported;
     }
 
     /* signature lookup */
     if (lookup && sic->mode != MODE_OFF) {
         /* iterate over every pair */
         for (i = 0; i < sic->nb_inputs; i++) {
             sc = &(sic->streamcontexts[i]);
             for (j = i+1; j < sic->nb_inputs; j++) {
                 sc2 = &(sic->streamcontexts[j]);
                 match = lookup_signatures(ctx, sic, sc, sc2, sic->mode);
                 if (match.score != 0) {
                     av_log(ctx, AV_LOG_INFO, "matching of video %d at %f and %d at %f, %d frames matching\n",
                             i, ((double) match.first->pts * sc->time_base.num) / sc->time_base.den,
                             j, ((double) match.second->pts * sc2->time_base.num) / sc2->time_base.den,
                             match.matchframes);
                     if (match.whole)
                         av_log(ctx, AV_LOG_INFO, "whole video matching\n");
                 } else {
                     av_log(ctx, AV_LOG_INFO, "no matching of video %d and %d\n", i, j);
                 }
             }
         }
     }
 
     return ret;
 }
 
 static av_cold int init(AVFilterContext *ctx)
 {
 
     SignatureContext *sic = ctx->priv;
     StreamContext *sc;
     int i, ret;
     char tmp[1024];
 
     sic->streamcontexts = av_mallocz(sic->nb_inputs * sizeof(StreamContext));
     if (!sic->streamcontexts)
         return AVERROR(ENOMEM);
 
     for (i = 0; i < sic->nb_inputs; i++) {
         AVFilterPad pad = {
             .type = AVMEDIA_TYPE_VIDEO,
             .name = av_asprintf("in%d", i),
             .config_props = config_input,
             .filter_frame = filter_frame,
         };
 
         if (!pad.name)
             return AVERROR(ENOMEM);
 
         sc = &(sic->streamcontexts[i]);
 
         sc->lastindex = 0;
         sc->finesiglist = av_mallocz(sizeof(FineSignature));
         if (!sc->finesiglist)
             return AVERROR(ENOMEM);
         sc->curfinesig = NULL;
 
         sc->coarsesiglist = av_mallocz(sizeof(CoarseSignature));
         if (!sc->coarsesiglist)
             return AVERROR(ENOMEM);
         sc->curcoarsesig1 = sc->coarsesiglist;
         sc->coarseend = sc->coarsesiglist;
         sc->coarsecount = 0;
         sc->midcoarse = 0;
 
         if ((ret = ff_insert_inpad(ctx, i, &pad)) < 0) {
             av_freep(&pad.name);
             return ret;
         }
     }
 
     /* check filename */
     if (sic->nb_inputs > 1 && strlen(sic->filename) > 0 && av_get_frame_filename(tmp, sizeof(tmp), sic->filename, 0) == -1) {
         av_log(ctx, AV_LOG_ERROR, "The filename must contain %%d or %%0nd, if you have more than one input.\n");
         return AVERROR(EINVAL);
     }
 
     return 0;
 }
 
 
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     SignatureContext *sic = ctx->priv;
     StreamContext *sc;
     void* tmp;
     FineSignature* finsig;
     CoarseSignature* cousig;
     int i;
 
 
     /* free the lists */
     if (sic->streamcontexts != NULL) {
         for (i = 0; i < sic->nb_inputs; i++) {
             sc = &(sic->streamcontexts[i]);
             finsig = sc->finesiglist;
             cousig = sc->coarsesiglist;
 
             while (finsig) {
                 tmp = finsig;
                 finsig = finsig->next;
                 av_freep(&tmp);
             }
             sc->finesiglist = NULL;
 
             while (cousig) {
                 tmp = cousig;
                 cousig = cousig->next;
                 av_freep(&tmp);
             }
             sc->coarsesiglist = NULL;
         }
         av_freep(&sic->streamcontexts);
     }
 }
 
 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     AVFilterLink *inlink = ctx->inputs[0];
 
     outlink->time_base = inlink->time_base;
     outlink->frame_rate = inlink->frame_rate;
     outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
     outlink->w = inlink->w;
     outlink->h = inlink->h;
 
     return 0;
 }
 
 static const AVFilterPad signature_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,
         .request_frame = request_frame,
         .config_props  = config_output,
     },
     { NULL }
 };
 
 AVFilter ff_vf_signature = {
     .name          = "signature",
     .description   = NULL_IF_CONFIG_SMALL("Calculate the MPEG-7 video signature"),
     .priv_size     = sizeof(SignatureContext),
     .priv_class    = &signature_class,
     .init          = init,
     .uninit        = uninit,
     .query_formats = query_formats,
     .outputs       = signature_outputs,
     .inputs        = NULL,
     .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS,
 };