/*
  * 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
  */
 

 #include "libavutil/avstring.h"

 #include "libavutil/channel_layout.h"
 #include "libavutil/eval.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"

 #include "libavutil/xga_font_data.h"

 #include "avfilter.h"
 #include "formats.h"
 #include "audio.h"
 #include "video.h"
 #include "internal.h"
 

 static const char *const var_names[] = {   "VOLUME",   "CHANNEL",   "PEAK",        NULL };
 enum                                   { VAR_VOLUME, VAR_CHANNEL, VAR_PEAK, VAR_VARS_NB };

 typedef struct ShowVolumeContext {
     const AVClass *class;
     int w, h;

     int b;
     double f;

     AVRational frame_rate;
     char *color;

     int orientation;
     int step;

 
     AVFrame *out;
     AVExpr *c_expr;

     int draw_text;

     int draw_volume;
     double *values;

     uint32_t *color_lut;

 } ShowVolumeContext;
 
 #define OFFSET(x) offsetof(ShowVolumeContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 
 static const AVOption showvolume_options[] = {

     { "rate", "set video rate",  OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, 0, INT_MAX, FLAGS },
     { "r",    "set video rate",  OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, 0, INT_MAX, FLAGS },

     { "b", "set border width",   OFFSET(b), AV_OPT_TYPE_INT, {.i64=1}, 0, 5, FLAGS },

     { "w", "set channel width",  OFFSET(w), AV_OPT_TYPE_INT, {.i64=400}, 80, 8192, FLAGS },
     { "h", "set channel height", OFFSET(h), AV_OPT_TYPE_INT, {.i64=20}, 1, 900, FLAGS },

     { "f", "set fade",           OFFSET(f), AV_OPT_TYPE_DOUBLE, {.dbl=0.95}, 0.001, 1, FLAGS },

     { "c", "set volume color expression", OFFSET(color), AV_OPT_TYPE_STRING, {.str="PEAK*255+floor((1-PEAK)*255)*256+0xff000000"}, 0, 0, FLAGS },

     { "t", "display channel names", OFFSET(draw_text), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },

     { "v", "display volume value", OFFSET(draw_volume), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },

     { "o", "set orientation", OFFSET(orientation), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS, "orientation" },
     {   "h", "horizontal", 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "orientation" },
     {   "v", "vertical",   0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "orientation" },
     { "s", "set step size", OFFSET(step), AV_OPT_TYPE_INT, {.i64=0}, 0, 5, FLAGS },

     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(showvolume);
 
 static av_cold int init(AVFilterContext *ctx)
 {
     ShowVolumeContext *s = ctx->priv;
     int ret;
 
     if (s->color) {
         ret = av_expr_parse(&s->c_expr, s->color, var_names,
                             NULL, NULL, NULL, NULL, 0, ctx);
         if (ret < 0)
             return ret;
     }
 
     return 0;
 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     AVFilterFormats *formats = NULL;
     AVFilterChannelLayouts *layouts = NULL;
     AVFilterLink *inlink = ctx->inputs[0];
     AVFilterLink *outlink = ctx->outputs[0];
     static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE };
     static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGBA, AV_PIX_FMT_NONE };

     int ret;

 
     formats = ff_make_format_list(sample_fmts);

     if ((ret = ff_formats_ref(formats, &inlink->out_formats)) < 0)
         return ret;

     layouts = ff_all_channel_counts();

     if ((ret = ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts)) < 0)
         return ret;

 
     formats = ff_all_samplerates();

     if ((ret = ff_formats_ref(formats, &inlink->out_samplerates)) < 0)
         return ret;

 
     formats = ff_make_format_list(pix_fmts);

     if ((ret = ff_formats_ref(formats, &outlink->in_formats)) < 0)
         return ret;

 
     return 0;
 }
 
 static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     ShowVolumeContext *s = ctx->priv;
     int nb_samples;
 
     nb_samples = FFMAX(1024, ((double)inlink->sample_rate / av_q2d(s->frame_rate)) + 0.5);
     inlink->partial_buf_size =
     inlink->min_samples =
     inlink->max_samples = nb_samples;

     s->values = av_calloc(inlink->channels * VAR_VARS_NB, sizeof(double));
     if (!s->values)
         return AVERROR(ENOMEM);

 
     s->color_lut = av_calloc(s->w, sizeof(*s->color_lut) * inlink->channels);
     if (!s->color_lut)
         return AVERROR(ENOMEM);
 

     return 0;
 }
 
 static int config_output(AVFilterLink *outlink)
 {
     ShowVolumeContext *s = outlink->src->priv;
     AVFilterLink *inlink = outlink->src->inputs[0];

     int ch;

     if (s->orientation) {
         outlink->h = s->w;
         outlink->w = s->h * inlink->channels + (inlink->channels - 1) * s->b;
     } else {
         outlink->w = s->w;
         outlink->h = s->h * inlink->channels + (inlink->channels - 1) * s->b;
     }
 

     outlink->sample_aspect_ratio = (AVRational){1,1};
     outlink->frame_rate = s->frame_rate;
 

     for (ch = 0; ch < inlink->channels; ch++) {
         int i;
 
         for (i = 0; i < s->w; i++) {
             float max = i / (float)(s->w - 1);
 
             s->values[ch * VAR_VARS_NB + VAR_PEAK] = max;
             s->values[ch * VAR_VARS_NB + VAR_VOLUME] = 20.0 * log10(max);
             s->values[ch * VAR_VARS_NB + VAR_CHANNEL] = ch;
             s->color_lut[ch * s->w + i] = av_expr_eval(s->c_expr, &s->values[ch * VAR_VARS_NB], NULL);
         }
     }
 

     return 0;
 }
 

 static void drawtext(AVFrame *pic, int x, int y, const char *txt, int o)

 {
     const uint8_t *font;
     int font_height;
     int i;
 
     font = avpriv_cga_font,   font_height =  8;
 
     for (i = 0; txt[i]; i++) {
         int char_y, mask;
 

         if (o) {
             for (char_y = font_height - 1; char_y >= 0; char_y--) {
                 uint8_t *p = pic->data[0] + (y + i * 10) * pic->linesize[0] + x * 4;
                 for (mask = 0x80; mask; mask >>= 1) {
                     if (font[txt[i] * font_height + font_height - 1 - char_y] & mask)
                         AV_WN32(&p[char_y * 4], ~AV_RN32(&p[char_y * 4]));
                     p += pic->linesize[0];
                 }
             }
         } else {
             uint8_t *p = pic->data[0] + y * pic->linesize[0] + (x + i * 8) * 4;
             for (char_y = 0; char_y < font_height; char_y++) {
                 for (mask = 0x80; mask; mask >>= 1) {
                     if (font[txt[i] * font_height + char_y] & mask)
                         AV_WN32(p, ~AV_RN32(p));
                     p += 4;
                 }
                 p += pic->linesize[0] - 8 * 4;

             }
         }
     }
 }
 

 static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
 {
     AVFilterContext *ctx = inlink->dst;
     AVFilterLink *outlink = ctx->outputs[0];
     ShowVolumeContext *s = ctx->priv;

     const int step = s->step;

     int c, i, j, k;

     AVFrame *out;

 
     if (!s->out || s->out->width  != outlink->w ||
                    s->out->height != outlink->h) {
         av_frame_free(&s->out);
         s->out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
         if (!s->out) {
             av_frame_free(&insamples);
             return AVERROR(ENOMEM);
         }
 
         for (i = 0; i < outlink->h; i++)
             memset(s->out->data[0] + i * s->out->linesize[0], 0, outlink->w * 4);
     }
     s->out->pts = insamples->pts;
 
     for (j = 0; j < outlink->h; j++) {
         uint8_t *dst = s->out->data[0] + j * s->out->linesize[0];

         for (k = 0; k < outlink->w; k++) {

             dst[k * 4 + 0] = FFMAX(dst[k * 4 + 0] * s->f, 0);
             dst[k * 4 + 1] = FFMAX(dst[k * 4 + 1] * s->f, 0);
             dst[k * 4 + 2] = FFMAX(dst[k * 4 + 2] * s->f, 0);
             dst[k * 4 + 3] = FFMAX(dst[k * 4 + 3] * s->f, 0);

         }
     }
 

     if (s->orientation) {
         for (c = 0; c < inlink->channels; c++) {
             float *src = (float *)insamples->extended_data[c];

             uint32_t *lut = s->color_lut + s->w * c;

             float max = 0;
 
             for (i = 0; i < insamples->nb_samples; i++)
                 max = FFMAX(max, src[i]);
 
             s->values[c * VAR_VARS_NB + VAR_VOLUME] = 20.0 * log10(max);
             max = av_clipf(max, 0, 1);
 

             for (j = outlink->h - outlink->h * max; j < s->w; j++) {

                 uint8_t *dst = s->out->data[0] + j * s->out->linesize[0] + c * (s->b + s->h) * 4;
                 for (k = 0; k < s->h; k++) {

                     AV_WN32A(&dst[k * 4], lut[s->w - j - 1]);

                     if (j & step)
                         j += step;
                 }
             }

             if (s->h >= 8 && s->draw_text) {

                 const char *channel_name = av_get_channel_name(av_channel_layout_extract_channel(insamples->channel_layout, c));
                 if (!channel_name)
                     continue;
                 drawtext(s->out, c * (s->h + s->b) + (s->h - 10) / 2, outlink->h - 35, channel_name, 1);
             }

         }

     } else {
         for (c = 0; c < inlink->channels; c++) {
             float *src = (float *)insamples->extended_data[c];

             uint32_t *lut = s->color_lut + s->w * c;

             float max = 0;
 
             for (i = 0; i < insamples->nb_samples; i++)
                 max = FFMAX(max, src[i]);
 
             s->values[c * VAR_VARS_NB + VAR_VOLUME] = 20.0 * log10(max);
             max = av_clipf(max, 0, 1);
 
             for (j = 0; j < s->h; j++) {
                 uint8_t *dst = s->out->data[0] + (c * s->h + c * s->b + j) * s->out->linesize[0];
 
                 for (k = 0; k < s->w * max; k++) {

                     AV_WN32A(dst + k * 4, lut[k]);

                     if (k & step)
                         k += step;
                 }
             }

             if (s->h >= 8 && s->draw_text) {
                 const char *channel_name = av_get_channel_name(av_channel_layout_extract_channel(insamples->channel_layout, c));
                 if (!channel_name)
                     continue;
                 drawtext(s->out, 2, c * (s->h + s->b) + (s->h - 8) / 2, channel_name, 0);
             }

         }

     }
 
     av_frame_free(&insamples);

     out = av_frame_clone(s->out);
     if (!out)
         return AVERROR(ENOMEM);
     av_frame_make_writable(out);
 
     for (c = 0; c < inlink->channels && s->draw_volume; c++) {

         char buf[16];
         if (s->orientation) {
             if (s->h >= 8) {
                 snprintf(buf, sizeof(buf), "%.2f", s->values[c * VAR_VARS_NB + VAR_VOLUME]);
                 drawtext(out, c * (s->h + s->b) + (s->h - 8) / 2, 2, buf, 1);
             }
         } else {
             if (s->h >= 8) {
                 snprintf(buf, sizeof(buf), "%.2f", s->values[c * VAR_VARS_NB + VAR_VOLUME]);
                 drawtext(out, FFMAX(0, s->w - 8 * (int)strlen(buf)), c * (s->h + s->b) + (s->h - 8) / 2, buf, 0);
             }

         }
     }

     return ff_filter_frame(outlink, out);

 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     ShowVolumeContext *s = ctx->priv;
 
     av_frame_free(&s->out);
     av_expr_free(s->c_expr);

     av_freep(&s->values);

     av_freep(&s->color_lut);

 }
 
 static const AVFilterPad showvolume_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_AUDIO,
         .config_props = config_input,
         .filter_frame = filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad showvolume_outputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_output,
     },
     { NULL }
 };
 
 AVFilter ff_avf_showvolume = {
     .name          = "showvolume",
     .description   = NULL_IF_CONFIG_SMALL("Convert input audio volume to video output."),
     .init          = init,
     .uninit        = uninit,
     .query_formats = query_formats,
     .priv_size     = sizeof(ShowVolumeContext),
     .inputs        = showvolume_inputs,
     .outputs       = showvolume_outputs,
     .priv_class    = &showvolume_class,
 };