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- /*
- * 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
- * Channel split filter
- *
- * Split an audio stream into per-channel streams.
- */
- #include "libavutil/attributes.h"
- #include "libavutil/channel_layout.h"
- #include "libavutil/internal.h"
- #include "libavutil/opt.h"
- #include "audio.h"
- #include "avfilter.h"
- #include "formats.h"
- #include "internal.h"
- typedef struct ChannelSplitContext {
- const AVClass *class;
- uint64_t channel_layout;
- char *channel_layout_str;
- } ChannelSplitContext;
- #define OFFSET(x) offsetof(ChannelSplitContext, x)
- #define A AV_OPT_FLAG_AUDIO_PARAM
- #define F AV_OPT_FLAG_FILTERING_PARAM
- static const AVOption channelsplit_options[] = {
- { "channel_layout", "Input channel layout.", OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, { .str = "stereo" }, .flags = A|F },
- { NULL }
- };
- AVFILTER_DEFINE_CLASS(channelsplit);
- static av_cold int init(AVFilterContext *ctx)
- {
- ChannelSplitContext *s = ctx->priv;
- int nb_channels;
- int ret = 0, i;
- if (!(s->channel_layout = av_get_channel_layout(s->channel_layout_str))) {
- av_log(ctx, AV_LOG_ERROR, "Error parsing channel layout '%s'.\n",
- s->channel_layout_str);
- ret = AVERROR(EINVAL);
- goto fail;
- }
- nb_channels = av_get_channel_layout_nb_channels(s->channel_layout);
- for (i = 0; i < nb_channels; i++) {
- uint64_t channel = av_channel_layout_extract_channel(s->channel_layout, i);
- AVFilterPad pad = { 0 };
- pad.type = AVMEDIA_TYPE_AUDIO;
- pad.name = av_get_channel_name(channel);
- ff_insert_outpad(ctx, i, &pad);
- }
- fail:
- return ret;
- }
- static int query_formats(AVFilterContext *ctx)
- {
- ChannelSplitContext *s = ctx->priv;
- AVFilterChannelLayouts *in_layouts = NULL;
- int i, ret;
- if ((ret = ff_set_common_formats(ctx, ff_planar_sample_fmts())) < 0 ||
- (ret = ff_set_common_samplerates(ctx, ff_all_samplerates())) < 0)
- return ret;
- if ((ret = ff_add_channel_layout(&in_layouts, s->channel_layout)) < 0 ||
- (ret = ff_channel_layouts_ref(in_layouts, &ctx->inputs[0]->out_channel_layouts)) < 0)
- return ret;
- for (i = 0; i < ctx->nb_outputs; i++) {
- AVFilterChannelLayouts *out_layouts = NULL;
- uint64_t channel = av_channel_layout_extract_channel(s->channel_layout, i);
- if ((ret = ff_add_channel_layout(&out_layouts, channel)) < 0 ||
- (ret = ff_channel_layouts_ref(out_layouts, &ctx->outputs[i]->in_channel_layouts)) < 0)
- return ret;
- }
- return 0;
- }
- static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
- {
- AVFilterContext *ctx = inlink->dst;
- int i, ret = 0;
- for (i = 0; i < ctx->nb_outputs; i++) {
- AVFrame *buf_out = av_frame_clone(buf);
- if (!buf_out) {
- ret = AVERROR(ENOMEM);
- break;
- }
- buf_out->data[0] = buf_out->extended_data[0] = buf_out->extended_data[i];
- buf_out->channel_layout =
- av_channel_layout_extract_channel(buf->channel_layout, i);
- av_frame_set_channels(buf_out, 1);
- ret = ff_filter_frame(ctx->outputs[i], buf_out);
- if (ret < 0)
- break;
- }
- av_frame_free(&buf);
- return ret;
- }
- static const AVFilterPad avfilter_af_channelsplit_inputs[] = {
- {
- .name = "default",
- .type = AVMEDIA_TYPE_AUDIO,
- .filter_frame = filter_frame,
- },
- { NULL }
- };
- AVFilter ff_af_channelsplit = {
- .name = "channelsplit",
- .description = NULL_IF_CONFIG_SMALL("Split audio into per-channel streams."),
- .priv_size = sizeof(ChannelSplitContext),
- .priv_class = &channelsplit_class,
- .init = init,
- .query_formats = query_formats,
- .inputs = avfilter_af_channelsplit_inputs,
- .outputs = NULL,
- .flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS,
- };
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