/*
  * Copyright (c) 2010 Stefano Sabatini
  * Copyright (c) 2008 Victor Paesa
  *
  * 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
  */
 
 /**
  * @file
  * video presentation timestamp (PTS) modification filter
  */
 

 #include <inttypes.h>
 

 #include "libavutil/eval.h"

 #include "libavutil/internal.h"

 #include "libavutil/mathematics.h"

 #include "libavutil/opt.h"

 #include "libavutil/time.h"

 #include "audio.h"

 #include "avfilter.h"

 #include "internal.h"

 #include "video.h"

 static const char *const var_names[] = {

     "FRAME_RATE",  ///< defined only for constant frame-rate video

     "INTERLACED",  ///< tell if the current frame is interlaced

     "N",           ///< frame / sample number (starting at zero)

     "NB_CONSUMED_SAMPLES", ///< number of samples consumed by the filter (only audio)
     "NB_SAMPLES",  ///< number of samples in the current frame (only audio)

     "POS",         ///< original position in the file of the frame
     "PREV_INPTS",  ///< previous  input PTS

     "PREV_INT",    ///< previous  input time in seconds

     "PREV_OUTPTS", ///< previous output PTS

     "PREV_OUTT",   ///< previous output time in seconds

     "PTS",         ///< original pts in the file of the frame

     "SAMPLE_RATE", ///< sample rate (only audio)
     "STARTPTS",    ///< PTS at start of movie

     "STARTT",      ///< time at start of movie
     "T",           ///< original time in the file of the frame

     "TB",          ///< timebase

     "RTCTIME",     ///< wallclock (RTC) time in micro seconds
     "RTCSTART",    ///< wallclock (RTC) time at the start of the movie in micro seconds

     "S",           //   Number of samples in the current frame
     "SR",          //   Audio sample rate

     NULL
 };
 
 enum var_name {

     VAR_FRAME_RATE,

     VAR_INTERLACED,
     VAR_N,

     VAR_NB_CONSUMED_SAMPLES,
     VAR_NB_SAMPLES,

     VAR_POS,
     VAR_PREV_INPTS,

     VAR_PREV_INT,

     VAR_PREV_OUTPTS,

     VAR_PREV_OUTT,

     VAR_PTS,

     VAR_SAMPLE_RATE,

     VAR_STARTPTS,

     VAR_STARTT,
     VAR_T,

     VAR_TB,

     VAR_RTCTIME,
     VAR_RTCSTART,

     VAR_S,
     VAR_SR,

     VAR_VARS_NB
 };
 

 typedef struct SetPTSContext {

     const AVClass *class;
     char *expr_str;

     AVExpr *expr;
     double var_values[VAR_VARS_NB];

     enum AVMediaType type;

 } SetPTSContext;
 

 static av_cold int init(AVFilterContext *ctx)

 {
     SetPTSContext *setpts = ctx->priv;
     int ret;
 

     if ((ret = av_expr_parse(&setpts->expr, setpts->expr_str,

                              var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) {

         av_log(ctx, AV_LOG_ERROR, "Error while parsing expression '%s'\n", setpts->expr_str);

         return ret;
     }
 

     setpts->var_values[VAR_N]           = 0.0;

     setpts->var_values[VAR_S]           = 0.0;

     setpts->var_values[VAR_PREV_INPTS]  = NAN;
     setpts->var_values[VAR_PREV_INT]    = NAN;
     setpts->var_values[VAR_PREV_OUTPTS] = NAN;
     setpts->var_values[VAR_PREV_OUTT]   = NAN;
     setpts->var_values[VAR_STARTPTS]    = NAN;
     setpts->var_values[VAR_STARTT]      = NAN;

     return 0;
 }
 
 static int config_input(AVFilterLink *inlink)
 {

     AVFilterContext *ctx = inlink->dst;
     SetPTSContext *setpts = ctx->priv;

     setpts->type = inlink->type;

     setpts->var_values[VAR_TB] = av_q2d(inlink->time_base);

     setpts->var_values[VAR_RTCSTART] = av_gettime();

     setpts->var_values[VAR_SR] =

     setpts->var_values[VAR_SAMPLE_RATE] =
         setpts->type == AVMEDIA_TYPE_AUDIO ? inlink->sample_rate : NAN;

     setpts->var_values[VAR_FRAME_RATE] = inlink->frame_rate.num &&
                                          inlink->frame_rate.den ?
                                             av_q2d(inlink->frame_rate) : NAN;

 
     av_log(inlink->src, AV_LOG_VERBOSE, "TB:%f FRAME_RATE:%f SAMPLE_RATE:%f\n",
            setpts->var_values[VAR_TB],
            setpts->var_values[VAR_FRAME_RATE],
            setpts->var_values[VAR_SAMPLE_RATE]);

     return 0;
 }
 
 #define D2TS(d)  (isnan(d) ? AV_NOPTS_VALUE : (int64_t)(d))
 #define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts))

 #define TS2T(ts, tb) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts)*av_q2d(tb))

 #define BUF_SIZE 64
 
 static inline char *double2int64str(char *buf, double v)
 {
     if (isnan(v)) snprintf(buf, BUF_SIZE, "nan");
     else          snprintf(buf, BUF_SIZE, "%"PRId64, (int64_t)v);
     return buf;
 }
 
 #define d2istr(v) double2int64str((char[BUF_SIZE]){0}, v)
 

 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)

 {
     SetPTSContext *setpts = inlink->dst->priv;

     int64_t in_pts = frame->pts;

     double d;

     if (isnan(setpts->var_values[VAR_STARTPTS])) {

         setpts->var_values[VAR_STARTPTS] = TS2D(frame->pts);
         setpts->var_values[VAR_STARTT  ] = TS2T(frame->pts, inlink->time_base);

     }

     setpts->var_values[VAR_PTS       ] = TS2D(frame->pts);
     setpts->var_values[VAR_T         ] = TS2T(frame->pts, inlink->time_base);

     setpts->var_values[VAR_POS       ] = av_frame_get_pkt_pos(frame) == -1 ? NAN : av_frame_get_pkt_pos(frame);

     setpts->var_values[VAR_RTCTIME   ] = av_gettime();

     if (inlink->type == AVMEDIA_TYPE_VIDEO) {

         setpts->var_values[VAR_INTERLACED] = frame->interlaced_frame;

     } else if (inlink->type == AVMEDIA_TYPE_AUDIO) {

         setpts->var_values[VAR_S] = frame->nb_samples;

         setpts->var_values[VAR_NB_SAMPLES] = frame->nb_samples;

     }
 

     d = av_expr_eval(setpts->expr, setpts->var_values, NULL);

     frame->pts = D2TS(d);

     av_log(inlink->dst, AV_LOG_TRACE,

             "N:%"PRId64" PTS:%s T:%f POS:%s",

             (int64_t)setpts->var_values[VAR_N],

             d2istr(setpts->var_values[VAR_PTS]),
             setpts->var_values[VAR_T],
             d2istr(setpts->var_values[VAR_POS]));

     switch (inlink->type) {
     case AVMEDIA_TYPE_VIDEO:

         av_log(inlink->dst, AV_LOG_TRACE, " INTERLACED:%"PRId64,

                 (int64_t)setpts->var_values[VAR_INTERLACED]);

         break;
     case AVMEDIA_TYPE_AUDIO:

         av_log(inlink->dst, AV_LOG_TRACE, " NB_SAMPLES:%"PRId64" NB_CONSUMED_SAMPLES:%"PRId64,

                 (int64_t)setpts->var_values[VAR_NB_SAMPLES],
                 (int64_t)setpts->var_values[VAR_NB_CONSUMED_SAMPLES]);

         break;
     }

     av_log(inlink->dst, AV_LOG_TRACE, " -> PTS:%s T:%f\n", d2istr(d), TS2T(d, inlink->time_base));

     if (inlink->type == AVMEDIA_TYPE_VIDEO) {
         setpts->var_values[VAR_N] += 1.0;
     } else {
         setpts->var_values[VAR_N] += frame->nb_samples;
     }

     setpts->var_values[VAR_PREV_INPTS ] = TS2D(in_pts);
     setpts->var_values[VAR_PREV_INT   ] = TS2T(in_pts, inlink->time_base);
     setpts->var_values[VAR_PREV_OUTPTS] = TS2D(frame->pts);
     setpts->var_values[VAR_PREV_OUTT]   = TS2T(frame->pts, inlink->time_base);

     if (setpts->type == AVMEDIA_TYPE_AUDIO) {

         setpts->var_values[VAR_NB_CONSUMED_SAMPLES] += frame->nb_samples;

     }
     return ff_filter_frame(inlink->dst->outputs[0], frame);

 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     SetPTSContext *setpts = ctx->priv;

     av_expr_free(setpts->expr);

     setpts->expr = NULL;
 }
 

 #define OFFSET(x) offsetof(SetPTSContext, x)

 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM

 static const AVOption options[] = {
     { "expr", "Expression determining the frame timestamp", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "PTS" }, .flags = FLAGS },

     { NULL }

 };
 

 #if CONFIG_SETPTS_FILTER

 #define setpts_options options
 AVFILTER_DEFINE_CLASS(setpts);

 static const AVFilterPad avfilter_vf_setpts_inputs[] = {

     {

         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_input,
         .filter_frame = filter_frame,

     },
     { NULL }
 };
 

 static const AVFilterPad avfilter_vf_setpts_outputs[] = {

     {
         .name = "default",

         .type = AVMEDIA_TYPE_VIDEO,

     },
     { NULL }
 };
 

 AVFilter ff_vf_setpts = {

     .name      = "setpts",
     .description = NULL_IF_CONFIG_SMALL("Set PTS for the output video frame."),

     .init      = init,
     .uninit    = uninit,
 

     .priv_size = sizeof(SetPTSContext),

     .priv_class = &setpts_class,

     .inputs    = avfilter_vf_setpts_inputs,
     .outputs   = avfilter_vf_setpts_outputs,

 };

 #endif /* CONFIG_SETPTS_FILTER */

 #if CONFIG_ASETPTS_FILTER

 #define asetpts_options options
 AVFILTER_DEFINE_CLASS(asetpts);

 static const AVFilterPad asetpts_inputs[] = {

     {

         .name         = "default",
         .type         = AVMEDIA_TYPE_AUDIO,
         .config_props = config_input,
         .filter_frame = filter_frame,

     },
     { NULL }
 };
 

 static const AVFilterPad asetpts_outputs[] = {

     {
         .name = "default",

         .type = AVMEDIA_TYPE_AUDIO,

     },
     { NULL }
 };
 

 AVFilter ff_af_asetpts = {

     .name        = "asetpts",
     .description = NULL_IF_CONFIG_SMALL("Set PTS for the output audio frame."),
     .init        = init,
     .uninit      = uninit,

     .priv_size   = sizeof(SetPTSContext),
     .priv_class  = &asetpts_class,
     .inputs      = asetpts_inputs,
     .outputs     = asetpts_outputs,

 };

 #endif /* CONFIG_ASETPTS_FILTER */