blob: f50414984a9e10ad71539fa60df2975cf9e93bc5
| 1 | /* |
| 2 | * This file is part of FFmpeg. |
| 3 | * |
| 4 | * FFmpeg is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU Lesser General Public |
| 6 | * License as published by the Free Software Foundation; either |
| 7 | * version 2.1 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * FFmpeg is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | * Lesser General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU Lesser General Public |
| 15 | * License along with FFmpeg; if not, write to the Free Software |
| 16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 17 | */ |
| 18 | |
| 19 | /** |
| 20 | * @file |
| 21 | * Channel split filter |
| 22 | * |
| 23 | * Split an audio stream into per-channel streams. |
| 24 | */ |
| 25 | |
| 26 | #include "libavutil/attributes.h" |
| 27 | #include "libavutil/channel_layout.h" |
| 28 | #include "libavutil/internal.h" |
| 29 | #include "libavutil/opt.h" |
| 30 | |
| 31 | #include "audio.h" |
| 32 | #include "avfilter.h" |
| 33 | #include "formats.h" |
| 34 | #include "internal.h" |
| 35 | |
| 36 | typedef struct ChannelSplitContext { |
| 37 | const AVClass *class; |
| 38 | |
| 39 | uint64_t channel_layout; |
| 40 | char *channel_layout_str; |
| 41 | } ChannelSplitContext; |
| 42 | |
| 43 | #define OFFSET(x) offsetof(ChannelSplitContext, x) |
| 44 | #define A AV_OPT_FLAG_AUDIO_PARAM |
| 45 | #define F AV_OPT_FLAG_FILTERING_PARAM |
| 46 | static const AVOption channelsplit_options[] = { |
| 47 | { "channel_layout", "Input channel layout.", OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, { .str = "stereo" }, .flags = A|F }, |
| 48 | { NULL } |
| 49 | }; |
| 50 | |
| 51 | AVFILTER_DEFINE_CLASS(channelsplit); |
| 52 | |
| 53 | static av_cold int init(AVFilterContext *ctx) |
| 54 | { |
| 55 | ChannelSplitContext *s = ctx->priv; |
| 56 | int nb_channels; |
| 57 | int ret = 0, i; |
| 58 | |
| 59 | if (!(s->channel_layout = av_get_channel_layout(s->channel_layout_str))) { |
| 60 | av_log(ctx, AV_LOG_ERROR, "Error parsing channel layout '%s'.\n", |
| 61 | s->channel_layout_str); |
| 62 | ret = AVERROR(EINVAL); |
| 63 | goto fail; |
| 64 | } |
| 65 | |
| 66 | nb_channels = av_get_channel_layout_nb_channels(s->channel_layout); |
| 67 | for (i = 0; i < nb_channels; i++) { |
| 68 | uint64_t channel = av_channel_layout_extract_channel(s->channel_layout, i); |
| 69 | AVFilterPad pad = { 0 }; |
| 70 | |
| 71 | pad.type = AVMEDIA_TYPE_AUDIO; |
| 72 | pad.name = av_get_channel_name(channel); |
| 73 | |
| 74 | ff_insert_outpad(ctx, i, &pad); |
| 75 | } |
| 76 | |
| 77 | fail: |
| 78 | return ret; |
| 79 | } |
| 80 | |
| 81 | static int query_formats(AVFilterContext *ctx) |
| 82 | { |
| 83 | ChannelSplitContext *s = ctx->priv; |
| 84 | AVFilterChannelLayouts *in_layouts = NULL; |
| 85 | int i, ret; |
| 86 | |
| 87 | if ((ret = ff_set_common_formats(ctx, ff_planar_sample_fmts())) < 0 || |
| 88 | (ret = ff_set_common_samplerates(ctx, ff_all_samplerates())) < 0) |
| 89 | return ret; |
| 90 | |
| 91 | if ((ret = ff_add_channel_layout(&in_layouts, s->channel_layout)) < 0 || |
| 92 | (ret = ff_channel_layouts_ref(in_layouts, &ctx->inputs[0]->out_channel_layouts)) < 0) |
| 93 | return ret; |
| 94 | |
| 95 | for (i = 0; i < ctx->nb_outputs; i++) { |
| 96 | AVFilterChannelLayouts *out_layouts = NULL; |
| 97 | uint64_t channel = av_channel_layout_extract_channel(s->channel_layout, i); |
| 98 | |
| 99 | if ((ret = ff_add_channel_layout(&out_layouts, channel)) < 0 || |
| 100 | (ret = ff_channel_layouts_ref(out_layouts, &ctx->outputs[i]->in_channel_layouts)) < 0) |
| 101 | return ret; |
| 102 | } |
| 103 | |
| 104 | return 0; |
| 105 | } |
| 106 | |
| 107 | static int filter_frame(AVFilterLink *inlink, AVFrame *buf) |
| 108 | { |
| 109 | AVFilterContext *ctx = inlink->dst; |
| 110 | int i, ret = 0; |
| 111 | |
| 112 | for (i = 0; i < ctx->nb_outputs; i++) { |
| 113 | AVFrame *buf_out = av_frame_clone(buf); |
| 114 | |
| 115 | if (!buf_out) { |
| 116 | ret = AVERROR(ENOMEM); |
| 117 | break; |
| 118 | } |
| 119 | |
| 120 | buf_out->data[0] = buf_out->extended_data[0] = buf_out->extended_data[i]; |
| 121 | buf_out->channel_layout = |
| 122 | av_channel_layout_extract_channel(buf->channel_layout, i); |
| 123 | av_frame_set_channels(buf_out, 1); |
| 124 | |
| 125 | ret = ff_filter_frame(ctx->outputs[i], buf_out); |
| 126 | if (ret < 0) |
| 127 | break; |
| 128 | } |
| 129 | av_frame_free(&buf); |
| 130 | return ret; |
| 131 | } |
| 132 | |
| 133 | static const AVFilterPad avfilter_af_channelsplit_inputs[] = { |
| 134 | { |
| 135 | .name = "default", |
| 136 | .type = AVMEDIA_TYPE_AUDIO, |
| 137 | .filter_frame = filter_frame, |
| 138 | }, |
| 139 | { NULL } |
| 140 | }; |
| 141 | |
| 142 | AVFilter ff_af_channelsplit = { |
| 143 | .name = "channelsplit", |
| 144 | .description = NULL_IF_CONFIG_SMALL("Split audio into per-channel streams."), |
| 145 | .priv_size = sizeof(ChannelSplitContext), |
| 146 | .priv_class = &channelsplit_class, |
| 147 | .init = init, |
| 148 | .query_formats = query_formats, |
| 149 | .inputs = avfilter_af_channelsplit_inputs, |
| 150 | .outputs = NULL, |
| 151 | .flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS, |
| 152 | }; |
| 153 |