/* * Copyright (c) 2012 Andrey Utkin * Copyright (c) 2012 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 * Filter that changes number of samples on single output operation */ #include "libavutil/channel_layout.h"#include "libavutil/opt.h"#include "avfilter.h"#include "audio.h"#include "filters.h" typedef struct ASNSContext {    const AVClass *class;    int nb_out_samples;  ///< how many samples to output    int pad;} ASNSContext; #define OFFSET(x) offsetof(ASNSContext, x)#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM static const AVOption asetnsamples_options[] = {    { "nb_out_samples", "set the number of per-frame output samples", OFFSET(nb_out_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },    { "n",              "set the number of per-frame output samples", OFFSET(nb_out_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },    { "pad", "pad last frame with zeros", OFFSET(pad), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },    { "p",   "pad last frame with zeros", OFFSET(pad), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },    { NULL }}; AVFILTER_DEFINE_CLASS(asetnsamples); static int activate(AVFilterContext *ctx){    AVFilterLink *inlink = ctx->inputs[0];    AVFilterLink *outlink = ctx->outputs[0];    ASNSContext *s = ctx->priv;    AVFrame *frame = NULL, *pad_frame;    int ret;     FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);     if (ctx->is_disabled)        ret = ff_inlink_consume_frame(inlink, &frame);    else        ret = ff_inlink_consume_samples(inlink, s->nb_out_samples, s->nb_out_samples, &frame);    if (ret < 0)        return ret;     if (ret > 0) {        if (!s->pad || ctx->is_disabled || frame->nb_samples == s->nb_out_samples)            return ff_filter_frame(outlink, frame);         pad_frame = ff_get_audio_buffer(outlink, s->nb_out_samples);        if (!pad_frame) {            av_frame_free(&frame);            return AVERROR(ENOMEM);        }         ret = av_frame_copy_props(pad_frame, frame);        if (ret < 0) {            av_frame_free(&pad_frame);            av_frame_free(&frame);            return ret;        }         av_samples_copy(pad_frame->extended_data, frame->extended_data,                        0, 0, frame->nb_samples, frame->ch_layout.nb_channels, frame->format);        av_samples_set_silence(pad_frame->extended_data, frame->nb_samples,                               s->nb_out_samples - frame->nb_samples, frame->ch_layout.nb_channels,                               frame->format);        av_frame_free(&frame);        return ff_filter_frame(outlink, pad_frame);    }     FF_FILTER_FORWARD_STATUS(inlink, outlink);    if (ff_inlink_queued_samples(inlink) >= s->nb_out_samples) {        ff_filter_set_ready(ctx, 100);        return 0;    }    FF_FILTER_FORWARD_WANTED(outlink, inlink);     return FFERROR_NOT_READY;} const FFFilter ff_af_asetnsamples = {    .p.name        = "asetnsamples",    .p.description = NULL_IF_CONFIG_SMALL("Set the number of samples for each output audio frames."),    .p.priv_class  = &asetnsamples_class,    .p.flags       = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,    .priv_size   = sizeof(ASNSContext),    FILTER_INPUTS(ff_audio_default_filterpad),    FILTER_OUTPUTS(ff_audio_default_filterpad),    .activate    = activate,    .process_command = ff_filter_process_command,};