| /* |
| * 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/mem.h" |
| #include "libavutil/opt.h" |
| |
| #include "audio.h" |
| #include "avfilter.h" |
| #include "filters.h" |
| #include "formats.h" |
| #include "internal.h" |
| |
| #define MAX_CH 64 |
| |
| typedef struct ChannelSplitContext { |
| const AVClass *class; |
| |
| AVChannelLayout channel_layout; |
| char *channels_str; |
| |
| int map[64]; |
| } 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), AV_OPT_TYPE_CHLAYOUT, { .str = "stereo" }, .flags = A|F }, |
| { "channels", "Channels to extract.", OFFSET(channels_str), AV_OPT_TYPE_STRING, { .str = "all" }, .flags = A|F }, |
| { NULL } |
| }; |
| |
| AVFILTER_DEFINE_CLASS(channelsplit); |
| |
| static av_cold int init(AVFilterContext *ctx) |
| { |
| ChannelSplitContext *s = ctx->priv; |
| AVChannelLayout channel_layout = { 0 }; |
| int all = 0, ret = 0, i; |
| |
| if (!strcmp(s->channels_str, "all")) { |
| if ((ret = av_channel_layout_copy(&channel_layout, &s->channel_layout)) < 0) |
| goto fail; |
| all = 1; |
| } else { |
| if ((ret = av_channel_layout_from_string(&channel_layout, s->channels_str)) < 0) |
| goto fail; |
| } |
| |
| if (channel_layout.nb_channels > MAX_CH) { |
| av_log(ctx, AV_LOG_ERROR, "Too many channels\n"); |
| goto fail; |
| } |
| |
| for (i = 0; i < channel_layout.nb_channels; i++) { |
| enum AVChannel channel = av_channel_layout_channel_from_index(&channel_layout, i); |
| char buf[64]; |
| AVFilterPad pad = { .flags = AVFILTERPAD_FLAG_FREE_NAME }; |
| |
| av_channel_name(buf, sizeof(buf), channel); |
| pad.type = AVMEDIA_TYPE_AUDIO; |
| pad.name = av_strdup(buf); |
| if (!pad.name) { |
| ret = AVERROR(ENOMEM); |
| goto fail; |
| } |
| |
| if (all) { |
| s->map[i] = i; |
| } else { |
| char buf[128]; |
| av_channel_layout_describe(&s->channel_layout, buf, sizeof(buf)); |
| if ((ret = av_channel_layout_index_from_channel(&s->channel_layout, channel)) < 0) { |
| av_log(ctx, AV_LOG_ERROR, "Channel name '%s' not present in channel layout '%s'.\n", |
| pad.name, buf); |
| av_freep(&pad.name); |
| goto fail; |
| } |
| |
| s->map[i] = ret; |
| } |
| |
| if ((ret = ff_append_outpad(ctx, &pad)) < 0) |
| goto fail; |
| } |
| |
| fail: |
| av_channel_layout_uninit(&channel_layout); |
| return ret; |
| } |
| |
| static av_cold void uninit(AVFilterContext *ctx) |
| { |
| ChannelSplitContext *s = ctx->priv; |
| |
| av_channel_layout_uninit(&s->channel_layout); |
| } |
| |
| 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_all_samplerates(ctx)) < 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]->outcfg.channel_layouts)) < 0) |
| return ret; |
| |
| for (i = 0; i < ctx->nb_outputs; i++) { |
| AVChannelLayout channel_layout = { 0 }; |
| AVFilterChannelLayouts *out_layouts = NULL; |
| enum AVChannel channel = av_channel_layout_channel_from_index(&s->channel_layout, s->map[i]); |
| |
| if ((ret = av_channel_layout_from_mask(&channel_layout, 1ULL << channel)) < 0 || |
| (ret = ff_add_channel_layout(&out_layouts, &channel_layout)) < 0 || |
| (ret = ff_channel_layouts_ref(out_layouts, &ctx->outputs[i]->incfg.channel_layouts)) < 0) |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int filter_frame(AVFilterLink *outlink, AVFrame *buf) |
| { |
| AVFilterContext *ctx = outlink->src; |
| ChannelSplitContext *s = ctx->priv; |
| const int i = FF_OUTLINK_IDX(outlink); |
| enum AVChannel channel = av_channel_layout_channel_from_index(&buf->ch_layout, s->map[i]); |
| int ret; |
| |
| AVFrame *buf_out = av_frame_clone(buf); |
| if (!buf_out) |
| return AVERROR(ENOMEM); |
| |
| buf_out->data[0] = buf_out->extended_data[0] = buf_out->extended_data[s->map[i]]; |
| ret = av_channel_layout_from_mask(&buf_out->ch_layout, 1ULL << channel); |
| if (ret < 0) { |
| av_frame_free(&buf_out); |
| return ret; |
| } |
| |
| return ff_filter_frame(ctx->outputs[i], buf_out); |
| } |
| |
| static int activate(AVFilterContext *ctx) |
| { |
| AVFilterLink *inlink = ctx->inputs[0]; |
| int status, ret; |
| AVFrame *in; |
| int64_t pts; |
| |
| for (int i = 0; i < ctx->nb_outputs; i++) { |
| FF_FILTER_FORWARD_STATUS_BACK_ALL(ctx->outputs[i], ctx); |
| } |
| |
| ret = ff_inlink_consume_frame(inlink, &in); |
| if (ret < 0) |
| return ret; |
| if (ret > 0) { |
| for (int i = 0; i < ctx->nb_outputs; i++) { |
| if (ff_outlink_get_status(ctx->outputs[i])) |
| continue; |
| |
| ret = filter_frame(ctx->outputs[i], in); |
| if (ret < 0) |
| break; |
| } |
| |
| av_frame_free(&in); |
| if (ret < 0) |
| return ret; |
| } |
| |
| if (ff_inlink_acknowledge_status(inlink, &status, &pts)) { |
| for (int i = 0; i < ctx->nb_outputs; i++) { |
| if (ff_outlink_get_status(ctx->outputs[i])) |
| continue; |
| ff_outlink_set_status(ctx->outputs[i], status, pts); |
| } |
| return 0; |
| } |
| |
| for (int i = 0; i < ctx->nb_outputs; i++) { |
| if (ff_outlink_get_status(ctx->outputs[i])) |
| continue; |
| |
| if (ff_outlink_frame_wanted(ctx->outputs[i])) { |
| ff_inlink_request_frame(inlink); |
| return 0; |
| } |
| } |
| |
| return FFERROR_NOT_READY; |
| } |
| |
| const 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, |
| .activate = activate, |
| .uninit = uninit, |
| FILTER_INPUTS(ff_audio_default_filterpad), |
| .outputs = NULL, |
| FILTER_QUERY_FUNC(query_formats), |
| .flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS, |
| }; |