libavfilter/asrc_aevalsrc.c - third_party/ffmpeg - Git at Google

 /*
  * Copyright (c) 2011 Stefano Sabatini
  *
  * 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
  * eval audio source
  */

 #include "libavutil/audioconvert.h"
 #include "libavutil/avassert.h"
 #include "libavutil/avstring.h"
 #include "libavutil/eval.h"
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"
 #include "avfilter.h"
 #include "internal.h"

 static const char * const var_names[] = {
     "n",            ///< number of frame
     "t",            ///< timestamp expressed in seconds
     "s",            ///< sample rate
     NULL
 };

 enum var_name {
     VAR_N,
     VAR_T,
     VAR_S,
     VAR_VARS_NB
 };

 typedef struct {
     const AVClass *class;
     char *sample_rate_str;
     int sample_rate;
     int64_t chlayout;
     int nb_channels;
     int64_t pts;
     AVExpr *expr[8];
     char *expr_str[8];
     int nb_samples;             ///< number of samples per requested frame
     char *duration_str;         ///< total duration of the generated audio
     double duration;
     uint64_t n;
     double var_values[VAR_VARS_NB];
 } EvalContext;

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

 static const AVOption eval_options[]= {
     { "nb_samples",  "set the number of samples per requested frame", OFFSET(nb_samples),      AV_OPT_TYPE_INT,    {.dbl = 1024},    0,        INT_MAX },
     { "n",           "set the number of samples per requested frame", OFFSET(nb_samples),      AV_OPT_TYPE_INT,    {.dbl = 1024},    0,        INT_MAX },
     { "sample_rate", "set the sample rate",                           OFFSET(sample_rate_str), AV_OPT_TYPE_STRING, {.str = "44100"}, CHAR_MIN, CHAR_MAX },
     { "s",           "set the sample rate",                           OFFSET(sample_rate_str), AV_OPT_TYPE_STRING, {.str = "44100"}, CHAR_MIN, CHAR_MAX },
     { "duration",    "set audio duration", OFFSET(duration_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
     { "d",           "set audio duration", OFFSET(duration_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
 {NULL},
 };

 static const char *eval_get_name(void *ctx)
 {
     return "aevalsrc";
 }

 static const AVClass eval_class = {
     "AEvalSrcContext",
     eval_get_name,
     eval_options
 };

 static int init(AVFilterContext *ctx, const char *args, void *opaque)
 {
     EvalContext *eval = ctx->priv;
     char *args1 = av_strdup(args);
     char *expr, *buf, *bufptr;
     int ret, i;

     eval->class = &eval_class;
     av_opt_set_defaults(eval);

     if (!args1) {
         av_log(ctx, AV_LOG_ERROR, "Argument is empty\n");
         ret = args ? AVERROR(ENOMEM) : AVERROR(EINVAL);
         goto end;
     }

     /* parse expressions */
     buf = args1;
     i = 0;
     while (expr = av_strtok(buf, ":", &bufptr)) {
         if (i >= 8) {
             av_log(ctx, AV_LOG_ERROR,
                    "More than 8 expressions provided, unsupported.\n");
             ret = AVERROR(EINVAL);
             return ret;
         }
         ret = av_expr_parse(&eval->expr[i], expr, var_names,
                             NULL, NULL, NULL, NULL, 0, ctx);
         if (ret < 0)
             goto end;
         i++;
         if (bufptr && *bufptr == ':') { /* found last expression */
             bufptr++;
             break;
         }
         buf = NULL;
     }

     /* guess channel layout from nb expressions/channels */
     eval->nb_channels = i;
     eval->chlayout = av_get_default_channel_layout(eval->nb_channels);
     if (!eval->chlayout) {
         av_log(ctx, AV_LOG_ERROR, "Invalid number of channels '%d' provided\n",
                eval->nb_channels);
         ret = AVERROR(EINVAL);
         goto end;
     }

     if (bufptr && (ret = av_set_options_string(eval, bufptr, "=", ":")) < 0)
         goto end;

     if ((ret = ff_parse_sample_rate(&eval->sample_rate, eval->sample_rate_str, ctx)))
         goto end;

     eval->duration = -1;
     if (eval->duration_str) {
         int64_t us = -1;
         if ((ret = av_parse_time(&us, eval->duration_str, 1)) < 0) {
             av_log(ctx, AV_LOG_ERROR, "Invalid duration: '%s'\n", eval->duration_str);
             goto end;
         }
         eval->duration = (double)us / 1000000;
     }
     eval->n = 0;

 end:
     av_free(args1);
     return ret;
 }

 static void uninit(AVFilterContext *ctx)
 {
     EvalContext *eval = ctx->priv;
     int i;

     for (i = 0; i < 8; i++) {
         av_expr_free(eval->expr[i]);
         eval->expr[i] = NULL;
     }
     av_freep(&eval->duration_str);
     av_freep(&eval->sample_rate_str);
 }

 static int config_props(AVFilterLink *outlink)
 {
     EvalContext *eval = outlink->src->priv;
     char buf[128];

     outlink->time_base = (AVRational){1, eval->sample_rate};
     outlink->sample_rate = eval->sample_rate;

     eval->var_values[VAR_S] = eval->sample_rate;

     av_get_channel_layout_string(buf, sizeof(buf), 0, eval->chlayout);

     av_log(outlink->src, AV_LOG_INFO,
            "sample_rate:%d chlayout:%s duration:%f\n",
            eval->sample_rate, buf, eval->duration);

     return 0;
 }

 static int query_formats(AVFilterContext *ctx)
 {
     EvalContext *eval = ctx->priv;
     enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_NONE };
     int64_t chlayouts[] = { eval->chlayout, -1 };
     int packing_fmts[] = { AVFILTER_PLANAR, -1 };

     avfilter_set_common_sample_formats (ctx, avfilter_make_format_list(sample_fmts));
     avfilter_set_common_channel_layouts(ctx, avfilter_make_format64_list(chlayouts));
     avfilter_set_common_packing_formats(ctx, avfilter_make_format_list(packing_fmts));

     return 0;
 }

 static int request_frame(AVFilterLink *outlink)
 {
     EvalContext *eval = outlink->src->priv;
     AVFilterBufferRef *samplesref;
     int i, j;
     double t = eval->var_values[VAR_N] * (double)1/eval->sample_rate;

     if (eval->duration >= 0 && t > eval->duration)
         return AVERROR_EOF;

     samplesref = avfilter_get_audio_buffer(outlink, AV_PERM_WRITE, eval->nb_samples);

     /* evaluate expression for each single sample and for each channel */
     for (i = 0; i < eval->nb_samples; i++, eval->n++) {
         eval->var_values[VAR_N] = eval->n;
         eval->var_values[VAR_T] = eval->var_values[VAR_N] * (double)1/eval->sample_rate;

         for (j = 0; j < eval->nb_channels; j++) {
             *((double *) samplesref->data[j] + i) =
                 av_expr_eval(eval->expr[j], eval->var_values, NULL);
         }
     }

     samplesref->pts = eval->pts;
     samplesref->pos = -1;
     samplesref->audio->sample_rate = eval->sample_rate;
     eval->pts += eval->nb_samples;

     avfilter_filter_samples(outlink, samplesref);

     return 0;
 }

 AVFilter avfilter_asrc_aevalsrc = {
     .name        = "aevalsrc",
     .description = NULL_IF_CONFIG_SMALL("Generate an audio signal generated by an expression."),

     .query_formats = query_formats,
     .init        = init,
     .uninit      = uninit,
     .priv_size   = sizeof(EvalContext),

     .inputs      = (const AVFilterPad[]) {{ .name = NULL}},

     .outputs     = (const AVFilterPad[]) {{ .name = "default",
                                       .type = AVMEDIA_TYPE_AUDIO,
                                       .config_props = config_props,
                                       .request_frame = request_frame, },
                                     { .name = NULL}},
 };
	/*
	* Copyright (c) 2011 Stefano Sabatini
	*
	* 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
	* eval audio source
	*/

	#include "libavutil/audioconvert.h"
	#include "libavutil/avassert.h"
	#include "libavutil/avstring.h"
	#include "libavutil/eval.h"
	#include "libavutil/opt.h"
	#include "libavutil/parseutils.h"
	#include "avfilter.h"
	#include "internal.h"

	static const char * const var_names[] = {
	"n", ///< number of frame
	"t", ///< timestamp expressed in seconds
	"s", ///< sample rate
	NULL
	};

	enum var_name {
	VAR_N,
	VAR_T,
	VAR_S,
	VAR_VARS_NB
	};

	typedef struct {
	const AVClass *class;
	char *sample_rate_str;
	int sample_rate;
	int64_t chlayout;
	int nb_channels;
	int64_t pts;
	AVExpr *expr[8];
	char *expr_str[8];
	int nb_samples; ///< number of samples per requested frame
	char *duration_str; ///< total duration of the generated audio
	double duration;
	uint64_t n;
	double var_values[VAR_VARS_NB];
	} EvalContext;

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

	static const AVOption eval_options[]= {
	{ "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.dbl = 1024}, 0, INT_MAX },
	{ "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.dbl = 1024}, 0, INT_MAX },
	{ "sample_rate", "set the sample rate", OFFSET(sample_rate_str), AV_OPT_TYPE_STRING, {.str = "44100"}, CHAR_MIN, CHAR_MAX },
	{ "s", "set the sample rate", OFFSET(sample_rate_str), AV_OPT_TYPE_STRING, {.str = "44100"}, CHAR_MIN, CHAR_MAX },
	{ "duration", "set audio duration", OFFSET(duration_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
	{ "d", "set audio duration", OFFSET(duration_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0 },
	{NULL},
	};

	static const char eval_get_name(void ctx)
	{
	return "aevalsrc";
	}

	static const AVClass eval_class = {
	"AEvalSrcContext",
	eval_get_name,
	eval_options
	};

	static int init(AVFilterContext ctx, const char args, void *opaque)
	{
	EvalContext *eval = ctx->priv;
	char *args1 = av_strdup(args);
	char expr, buf, *bufptr;
	int ret, i;

	eval->class = &eval_class;
	av_opt_set_defaults(eval);

	if (!args1) {
	av_log(ctx, AV_LOG_ERROR, "Argument is empty\n");
	ret = args ? AVERROR(ENOMEM) : AVERROR(EINVAL);
	goto end;
	}

	/* parse expressions */
	buf = args1;
	i = 0;
	while (expr = av_strtok(buf, ":", &bufptr)) {
	if (i >= 8) {
	av_log(ctx, AV_LOG_ERROR,
	"More than 8 expressions provided, unsupported.\n");
	ret = AVERROR(EINVAL);
	return ret;
	}
	ret = av_expr_parse(&eval->expr[i], expr, var_names,
	NULL, NULL, NULL, NULL, 0, ctx);
	if (ret < 0)
	goto end;
	i++;
	if (bufptr && bufptr == ':') { / found last expression */
	bufptr++;
	break;
	}
	buf = NULL;
	}

	/* guess channel layout from nb expressions/channels */
	eval->nb_channels = i;
	eval->chlayout = av_get_default_channel_layout(eval->nb_channels);
	if (!eval->chlayout) {
	av_log(ctx, AV_LOG_ERROR, "Invalid number of channels '%d' provided\n",
	eval->nb_channels);
	ret = AVERROR(EINVAL);
	goto end;
	}

	if (bufptr && (ret = av_set_options_string(eval, bufptr, "=", ":")) < 0)
	goto end;

	if ((ret = ff_parse_sample_rate(&eval->sample_rate, eval->sample_rate_str, ctx)))
	goto end;

	eval->duration = -1;
	if (eval->duration_str) {
	int64_t us = -1;
	if ((ret = av_parse_time(&us, eval->duration_str, 1)) < 0) {
	av_log(ctx, AV_LOG_ERROR, "Invalid duration: '%s'\n", eval->duration_str);
	goto end;
	}
	eval->duration = (double)us / 1000000;
	}
	eval->n = 0;

	end:
	av_free(args1);
	return ret;
	}

	static void uninit(AVFilterContext *ctx)
	{
	EvalContext *eval = ctx->priv;
	int i;

	for (i = 0; i < 8; i++) {
	av_expr_free(eval->expr[i]);
	eval->expr[i] = NULL;
	}
	av_freep(&eval->duration_str);
	av_freep(&eval->sample_rate_str);
	}

	static int config_props(AVFilterLink *outlink)
	{
	EvalContext *eval = outlink->src->priv;
	char buf[128];

	outlink->time_base = (AVRational){1, eval->sample_rate};
	outlink->sample_rate = eval->sample_rate;

	eval->var_values[VAR_S] = eval->sample_rate;

	av_get_channel_layout_string(buf, sizeof(buf), 0, eval->chlayout);

	av_log(outlink->src, AV_LOG_INFO,
	"sample_rate:%d chlayout:%s duration:%f\n",
	eval->sample_rate, buf, eval->duration);

	return 0;
	}

	static int query_formats(AVFilterContext *ctx)
	{
	EvalContext *eval = ctx->priv;
	enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_NONE };
	int64_t chlayouts[] = { eval->chlayout, -1 };
	int packing_fmts[] = { AVFILTER_PLANAR, -1 };

	avfilter_set_common_sample_formats (ctx, avfilter_make_format_list(sample_fmts));
	avfilter_set_common_channel_layouts(ctx, avfilter_make_format64_list(chlayouts));
	avfilter_set_common_packing_formats(ctx, avfilter_make_format_list(packing_fmts));

	return 0;
	}

	static int request_frame(AVFilterLink *outlink)
	{
	EvalContext *eval = outlink->src->priv;
	AVFilterBufferRef *samplesref;
	int i, j;
	double t = eval->var_values[VAR_N] * (double)1/eval->sample_rate;

	if (eval->duration >= 0 && t > eval->duration)
	return AVERROR_EOF;

	samplesref = avfilter_get_audio_buffer(outlink, AV_PERM_WRITE, eval->nb_samples);

	/* evaluate expression for each single sample and for each channel */
	for (i = 0; i < eval->nb_samples; i++, eval->n++) {
	eval->var_values[VAR_N] = eval->n;
	eval->var_values[VAR_T] = eval->var_values[VAR_N] * (double)1/eval->sample_rate;

	for (j = 0; j < eval->nb_channels; j++) {
	((double ) samplesref->data[j] + i) =
	av_expr_eval(eval->expr[j], eval->var_values, NULL);
	}
	}

	samplesref->pts = eval->pts;
	samplesref->pos = -1;
	samplesref->audio->sample_rate = eval->sample_rate;
	eval->pts += eval->nb_samples;

	avfilter_filter_samples(outlink, samplesref);

	return 0;
	}

	AVFilter avfilter_asrc_aevalsrc = {
	.name = "aevalsrc",
	.description = NULL_IF_CONFIG_SMALL("Generate an audio signal generated by an expression."),

	.query_formats = query_formats,
	.init = init,
	.uninit = uninit,
	.priv_size = sizeof(EvalContext),

	.inputs = (const AVFilterPad[]) {{ .name = NULL}},

	.outputs = (const AVFilterPad[]) {{ .name = "default",
	.type = AVMEDIA_TYPE_AUDIO,
	.config_props = config_props,
	.request_frame = request_frame, },
	{ .name = NULL}},
	};