/* * Copyright (c) 2012 Michael Niedermayer * * 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 * audio pad filter. * * Based on af_aresample.c */ #include "libavutil/avstring.h"#include "libavutil/channel_layout.h"#include "libavutil/opt.h"#include "libavutil/samplefmt.h"#include "libavutil/avassert.h"#include "avfilter.h"#include "audio.h"#include "filters.h" typedef struct APadContext {    const AVClass *class;    int64_t next_pts;     int eof;    int packet_size;    int64_t pad_len, pad_len_left;    int64_t whole_len, whole_len_left;    int64_t pad_dur;    int64_t whole_dur;} APadContext; #define OFFSET(x) offsetof(APadContext, x)#define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM static const AVOption apad_options[] = {    { "packet_size", "set silence packet size",                                  OFFSET(packet_size), AV_OPT_TYPE_INT,   { .i64 = 4096 }, 0, INT_MAX, A },    { "pad_len",     "set number of samples of silence to add",                  OFFSET(pad_len),     AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, A },    { "whole_len",   "set minimum target number of samples in the audio stream", OFFSET(whole_len),   AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, A },    { "pad_dur",     "set duration of silence to add",                           OFFSET(pad_dur),     AV_OPT_TYPE_DURATION, { .i64 = -1 }, -1, INT64_MAX, A },    { "whole_dur",   "set minimum target duration in the audio stream",          OFFSET(whole_dur),   AV_OPT_TYPE_DURATION, { .i64 = -1 }, -1, INT64_MAX, A },    { NULL }}; AVFILTER_DEFINE_CLASS(apad); static av_cold int init(AVFilterContext *ctx){    APadContext *s = ctx->priv;     s->next_pts = AV_NOPTS_VALUE;    if (s->whole_len >= 0 && s->pad_len >= 0) {        av_log(ctx, AV_LOG_ERROR, "Both whole and pad length are set, this is not possible\n");        return AVERROR(EINVAL);    }     return 0;} static int filter_frame(AVFilterLink *inlink, AVFrame *frame){    AVFilterContext *ctx = inlink->dst;    APadContext *s = ctx->priv;     if (s->whole_len >= 0) {        s->whole_len_left = FFMAX(s->whole_len_left - frame->nb_samples, 0);        av_log(ctx, AV_LOG_DEBUG,               "n_out:%d whole_len_left:%"PRId64"\n", frame->nb_samples, s->whole_len_left);    }     s->next_pts = frame->pts + av_rescale_q(frame->nb_samples, (AVRational){1, inlink->sample_rate}, inlink->time_base);    return ff_filter_frame(ctx->outputs[0], frame);} static int push_frame(AVFilterLink *outlink){    AVFilterContext *ctx = outlink->src;    APadContext *s = ctx->priv;    AVFrame *outsamplesref;    int n_out;     if (ctx->is_disabled)        return 0;    n_out = s->packet_size;     if (s->whole_len >= 0 && s->pad_len < 0) {        s->pad_len = s->pad_len_left = s->whole_len_left;    }    if (s->pad_len >=0 || s->whole_len >= 0) {        n_out = FFMIN(n_out, s->pad_len_left);        s->pad_len_left -= n_out;        av_log(ctx, AV_LOG_DEBUG,               "padding n_out:%d pad_len_left:%"PRId64"\n", n_out, s->pad_len_left);    }     if (!n_out)        return AVERROR_EOF;     outsamplesref = ff_get_audio_buffer(outlink, n_out);    if (!outsamplesref)        return AVERROR(ENOMEM);     av_assert0(outsamplesref->sample_rate == outlink->sample_rate);    av_assert0(outsamplesref->nb_samples  == n_out);     av_samples_set_silence(outsamplesref->extended_data, 0,                           n_out,                           outsamplesref->ch_layout.nb_channels,                           outsamplesref->format);     outsamplesref->pts = s->next_pts;    if (s->next_pts != AV_NOPTS_VALUE)        s->next_pts += av_rescale_q(n_out, (AVRational){1, outlink->sample_rate}, outlink->time_base);     return ff_filter_frame(outlink, outsamplesref);} static int activate(AVFilterContext *ctx){    AVFilterLink *inlink = ctx->inputs[0];    AVFilterLink *outlink = ctx->outputs[0];    APadContext *s = ctx->priv;    int64_t pts;    int status;     FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);     if (!s->eof && ff_inlink_queued_frames(inlink)) {        AVFrame *frame = NULL;        int ret;         ret = ff_inlink_consume_frame(inlink, &frame);        if (ret < 0)            return ret;        if (ret > 0)            return filter_frame(inlink, frame);    }     if (!s->eof && ff_inlink_acknowledge_status(inlink, &status, &pts))        s->eof = status == AVERROR_EOF;     if (s->eof) {        int ret = push_frame(outlink);         if (ret == AVERROR_EOF) {            ff_outlink_set_status(outlink, AVERROR_EOF, s->next_pts);            return 0;        }        return ret;    }     FF_FILTER_FORWARD_WANTED(outlink, inlink);     return FFERROR_NOT_READY;} static int config_output(AVFilterLink *outlink){    AVFilterContext *ctx = outlink->src;    APadContext *s  = ctx->priv;     if (s->pad_dur >= 0)        s->pad_len = av_rescale(s->pad_dur, outlink->sample_rate, AV_TIME_BASE);    if (s->whole_dur >= 0)        s->whole_len = av_rescale(s->whole_dur, outlink->sample_rate, AV_TIME_BASE);     s->pad_len_left   = s->pad_len;    s->whole_len_left = s->whole_len;     return 0;} static const AVFilterPad apad_outputs[] = {    {        .name          = "default",        .type          = AVMEDIA_TYPE_AUDIO,        .config_props  = config_output,    },}; const FFFilter ff_af_apad = {    .p.name        = "apad",    .p.description = NULL_IF_CONFIG_SMALL("Pad audio with silence."),    .p.priv_class  = &apad_class,    .p.flags       = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,    .init          = init,    .activate      = activate,    .priv_size     = sizeof(APadContext),    FILTER_INPUTS(ff_audio_default_filterpad),    FILTER_OUTPUTS(apad_outputs),};