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Diffstat (limited to 'libavfilter/asrc_aevalsrc.c')
| -rw-r--r-- | libavfilter/asrc_aevalsrc.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/libavfilter/asrc_aevalsrc.c b/libavfilter/asrc_aevalsrc.c new file mode 100644 index 0000000000..c8b5e02700 --- /dev/null +++ b/libavfilter/asrc_aevalsrc.c @@ -0,0 +1,262 @@ +/* + * 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 "audio.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; + char *chlayout_str; + 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) +#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM + +static const AVOption aevalsrc_options[]= { + { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 0, INT_MAX, FLAGS }, + { "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 0, INT_MAX, FLAGS }, + { "sample_rate", "set the sample rate", OFFSET(sample_rate_str), AV_OPT_TYPE_STRING, {.str = "44100"}, CHAR_MIN, CHAR_MAX, FLAGS }, + { "s", "set the sample rate", OFFSET(sample_rate_str), AV_OPT_TYPE_STRING, {.str = "44100"}, CHAR_MIN, CHAR_MAX, FLAGS }, + { "duration", "set audio duration", OFFSET(duration_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS }, + { "d", "set audio duration", OFFSET(duration_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS }, + { "channel_layout", "set channel layout", OFFSET(chlayout_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS }, + { "c", "set channel layout", OFFSET(chlayout_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS }, +{NULL}, +}; + +AVFILTER_DEFINE_CLASS(aevalsrc); + +static int init(AVFilterContext *ctx, const char *args) +{ + EvalContext *eval = ctx->priv; + char *args1 = av_strdup(args); + char *expr, *buf, *bufptr; + int ret, i; + + eval->class = &aevalsrc_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)) { + 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; + } + eval->nb_channels = i; + + if (bufptr && (ret = av_set_options_string(eval, bufptr, "=", ":")) < 0) + goto end; + + if (eval->chlayout_str) { + int n; + ret = ff_parse_channel_layout(&eval->chlayout, eval->chlayout_str, ctx); + if (ret < 0) + goto end; + + n = av_get_channel_layout_nb_channels(eval->chlayout); + if (n != eval->nb_channels) { + av_log(ctx, AV_LOG_ERROR, + "Mismatch between the specified number of channels '%d' " + "and the number of channels '%d' in the specified channel layout '%s'\n", + eval->nb_channels, n, eval->chlayout_str); + ret = AVERROR(EINVAL); + goto end; + } + } else { + /* guess channel layout from nb expressions/channels */ + 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 ((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->chlayout_str); + 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_VERBOSE, + "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_DBLP, AV_SAMPLE_FMT_NONE }; + int64_t chlayouts[] = { eval->chlayout, -1 }; + int sample_rates[] = { eval->sample_rate, -1 }; + + ff_set_common_formats (ctx, ff_make_format_list(sample_fmts)); + ff_set_common_channel_layouts(ctx, avfilter_make_format64_list(chlayouts)); + ff_set_common_samplerates(ctx, ff_make_format_list(sample_rates)); + + 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 = ff_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->extended_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; + + ff_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}}, + .priv_class = &aevalsrc_class, +}; |