yading@10: /* yading@10: * Copyright (c) 2012 Michael Niedermayer yading@10: * yading@10: * This file is part of FFmpeg. yading@10: * yading@10: * FFmpeg is free software; you can redistribute it and/or yading@10: * modify it under the terms of the GNU Lesser General Public yading@10: * License as published by the Free Software Foundation; either yading@10: * version 2.1 of the License, or (at your option) any later version. yading@10: * yading@10: * FFmpeg is distributed in the hope that it will be useful, yading@10: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@10: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@10: * Lesser General Public License for more details. yading@10: * yading@10: * You should have received a copy of the GNU Lesser General Public yading@10: * License along with FFmpeg; if not, write to the Free Software yading@10: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@10: * yading@10: */ yading@10: yading@10: /** yading@10: * @file yading@10: * audio pad filter. yading@10: * yading@10: * Based on af_aresample.c yading@10: */ yading@10: yading@10: #include "libavutil/avstring.h" yading@10: #include "libavutil/channel_layout.h" yading@10: #include "libavutil/opt.h" yading@10: #include "libavutil/samplefmt.h" yading@10: #include "libavutil/avassert.h" yading@10: #include "avfilter.h" yading@10: #include "audio.h" yading@10: #include "internal.h" yading@10: yading@10: typedef struct { yading@10: const AVClass *class; yading@10: int64_t next_pts; yading@10: yading@10: int packet_size; yading@10: int64_t pad_len; yading@10: int64_t whole_len; yading@10: } APadContext; yading@10: yading@10: #define OFFSET(x) offsetof(APadContext, x) yading@10: #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM yading@10: yading@10: static const AVOption apad_options[] = { yading@10: { "packet_size", "set silence packet size", OFFSET(packet_size), AV_OPT_TYPE_INT, { .i64 = 4096 }, 0, INT_MAX, A }, yading@10: { "pad_len", "number of samples of silence to add", OFFSET(pad_len), AV_OPT_TYPE_INT64, { .i64 = 0 }, 0, INT64_MAX, A }, yading@10: { "whole_len", "target number of samples in the audio stream", OFFSET(whole_len), AV_OPT_TYPE_INT64, { .i64 = 0 }, 0, INT64_MAX, A }, yading@10: { NULL }, yading@10: }; yading@10: yading@10: AVFILTER_DEFINE_CLASS(apad); yading@10: yading@10: static av_cold int init(AVFilterContext *ctx) yading@10: { yading@10: APadContext *apad = ctx->priv; yading@10: yading@10: apad->next_pts = AV_NOPTS_VALUE; yading@10: if (apad->whole_len && apad->pad_len) { yading@10: av_log(ctx, AV_LOG_ERROR, "Both whole and pad length are set, this is not possible\n"); yading@10: return AVERROR(EINVAL); yading@10: } yading@10: yading@10: return 0; yading@10: } yading@10: yading@10: static int filter_frame(AVFilterLink *inlink, AVFrame *frame) yading@10: { yading@10: AVFilterContext *ctx = inlink->dst; yading@10: APadContext *apad = ctx->priv; yading@10: yading@10: if (apad->whole_len) yading@10: apad->whole_len -= frame->nb_samples; yading@10: yading@10: apad->next_pts = frame->pts + av_rescale_q(frame->nb_samples, (AVRational){1, inlink->sample_rate}, inlink->time_base); yading@10: return ff_filter_frame(ctx->outputs[0], frame); yading@10: } yading@10: yading@10: static int request_frame(AVFilterLink *outlink) yading@10: { yading@10: AVFilterContext *ctx = outlink->src; yading@10: APadContext *apad = ctx->priv; yading@10: int ret; yading@10: yading@10: ret = ff_request_frame(ctx->inputs[0]); yading@10: yading@10: if (ret == AVERROR_EOF) { yading@10: int n_out = apad->packet_size; yading@10: AVFrame *outsamplesref; yading@10: yading@10: if (apad->whole_len > 0) { yading@10: apad->pad_len = apad->whole_len; yading@10: apad->whole_len = 0; yading@10: } yading@10: if (apad->pad_len > 0) { yading@10: n_out = FFMIN(n_out, apad->pad_len); yading@10: apad->pad_len -= n_out; yading@10: } yading@10: yading@10: if(!n_out) yading@10: return AVERROR_EOF; yading@10: yading@10: outsamplesref = ff_get_audio_buffer(outlink, n_out); yading@10: if (!outsamplesref) yading@10: return AVERROR(ENOMEM); yading@10: yading@10: av_assert0(outsamplesref->sample_rate == outlink->sample_rate); yading@10: av_assert0(outsamplesref->nb_samples == n_out); yading@10: yading@10: av_samples_set_silence(outsamplesref->extended_data, 0, yading@10: n_out, yading@10: av_frame_get_channels(outsamplesref), yading@10: outsamplesref->format); yading@10: yading@10: outsamplesref->pts = apad->next_pts; yading@10: if (apad->next_pts != AV_NOPTS_VALUE) yading@10: apad->next_pts += av_rescale_q(n_out, (AVRational){1, outlink->sample_rate}, outlink->time_base); yading@10: yading@10: return ff_filter_frame(outlink, outsamplesref); yading@10: } yading@10: return ret; yading@10: } yading@10: yading@10: static const AVFilterPad apad_inputs[] = { yading@10: { yading@10: .name = "default", yading@10: .type = AVMEDIA_TYPE_AUDIO, yading@10: .filter_frame = filter_frame, yading@10: }, yading@10: { NULL }, yading@10: }; yading@10: yading@10: static const AVFilterPad apad_outputs[] = { yading@10: { yading@10: .name = "default", yading@10: .request_frame = request_frame, yading@10: .type = AVMEDIA_TYPE_AUDIO, yading@10: }, yading@10: { NULL }, yading@10: }; yading@10: yading@10: AVFilter avfilter_af_apad = { yading@10: .name = "apad", yading@10: .description = NULL_IF_CONFIG_SMALL("Pad audio with silence."), yading@10: .init = init, yading@10: .priv_size = sizeof(APadContext), yading@10: .inputs = apad_inputs, yading@10: .outputs = apad_outputs, yading@10: .priv_class = &apad_class, yading@10: };