| 1 | /* |
| 2 | * Copyright (c) 2011 Nicolas George <nicolas.george@normalesup.org> |
| 3 | * |
| 4 | * This file is part of FFmpeg. |
| 5 | * |
| 6 | * FFmpeg is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * FFmpeg is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with FFmpeg; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | /** |
| 22 | * @file |
| 23 | * Stream (de)synchronization filter |
| 24 | */ |
| 25 | |
| 26 | #include "libavutil/eval.h" |
| 27 | #include "libavutil/opt.h" |
| 28 | #include "avfilter.h" |
| 29 | #include "audio.h" |
| 30 | #include "internal.h" |
| 31 | |
| 32 | #define QUEUE_SIZE 16 |
| 33 | |
| 34 | static const char * const var_names[] = { |
| 35 | "b1", "b2", |
| 36 | "s1", "s2", |
| 37 | "t1", "t2", |
| 38 | NULL |
| 39 | }; |
| 40 | |
| 41 | enum var_name { |
| 42 | VAR_B1, VAR_B2, |
| 43 | VAR_S1, VAR_S2, |
| 44 | VAR_T1, VAR_T2, |
| 45 | VAR_NB |
| 46 | }; |
| 47 | |
| 48 | typedef struct { |
| 49 | const AVClass *class; |
| 50 | AVExpr *expr; |
| 51 | char *expr_str; |
| 52 | double var_values[VAR_NB]; |
| 53 | struct buf_queue { |
| 54 | AVFrame *buf[QUEUE_SIZE]; |
| 55 | unsigned tail, nb; |
| 56 | /* buf[tail] is the oldest, |
| 57 | buf[(tail + nb) % QUEUE_SIZE] is where the next is added */ |
| 58 | } queue[2]; |
| 59 | int req[2]; |
| 60 | int next_out; |
| 61 | int eof; /* bitmask, one bit for each stream */ |
| 62 | } AStreamSyncContext; |
| 63 | |
| 64 | #define OFFSET(x) offsetof(AStreamSyncContext, x) |
| 65 | #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM |
| 66 | static const AVOption astreamsync_options[] = { |
| 67 | { "expr", "set stream selection expression", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "t1-t2" }, .flags = FLAGS }, |
| 68 | { "e", "set stream selection expression", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "t1-t2" }, .flags = FLAGS }, |
| 69 | { NULL } |
| 70 | }; |
| 71 | |
| 72 | AVFILTER_DEFINE_CLASS(astreamsync); |
| 73 | |
| 74 | static av_cold int init(AVFilterContext *ctx) |
| 75 | { |
| 76 | AStreamSyncContext *as = ctx->priv; |
| 77 | int r, i; |
| 78 | |
| 79 | r = av_expr_parse(&as->expr, as->expr_str, var_names, |
| 80 | NULL, NULL, NULL, NULL, 0, ctx); |
| 81 | if (r < 0) { |
| 82 | av_log(ctx, AV_LOG_ERROR, "Error in expression \"%s\"\n", as->expr_str); |
| 83 | return r; |
| 84 | } |
| 85 | for (i = 0; i < 42; i++) |
| 86 | av_expr_eval(as->expr, as->var_values, NULL); /* exercize prng */ |
| 87 | return 0; |
| 88 | } |
| 89 | |
| 90 | static int query_formats(AVFilterContext *ctx) |
| 91 | { |
| 92 | int i; |
| 93 | AVFilterFormats *formats, *rates; |
| 94 | AVFilterChannelLayouts *layouts; |
| 95 | |
| 96 | for (i = 0; i < 2; i++) { |
| 97 | formats = ctx->inputs[i]->in_formats; |
| 98 | ff_formats_ref(formats, &ctx->inputs[i]->out_formats); |
| 99 | ff_formats_ref(formats, &ctx->outputs[i]->in_formats); |
| 100 | rates = ff_all_samplerates(); |
| 101 | ff_formats_ref(rates, &ctx->inputs[i]->out_samplerates); |
| 102 | ff_formats_ref(rates, &ctx->outputs[i]->in_samplerates); |
| 103 | layouts = ctx->inputs[i]->in_channel_layouts; |
| 104 | ff_channel_layouts_ref(layouts, &ctx->inputs[i]->out_channel_layouts); |
| 105 | ff_channel_layouts_ref(layouts, &ctx->outputs[i]->in_channel_layouts); |
| 106 | } |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | static int config_output(AVFilterLink *outlink) |
| 111 | { |
| 112 | AVFilterContext *ctx = outlink->src; |
| 113 | int id = outlink == ctx->outputs[1]; |
| 114 | |
| 115 | outlink->sample_rate = ctx->inputs[id]->sample_rate; |
| 116 | outlink->time_base = ctx->inputs[id]->time_base; |
| 117 | return 0; |
| 118 | } |
| 119 | |
| 120 | static int send_out(AVFilterContext *ctx, int out_id) |
| 121 | { |
| 122 | AStreamSyncContext *as = ctx->priv; |
| 123 | struct buf_queue *queue = &as->queue[out_id]; |
| 124 | AVFrame *buf = queue->buf[queue->tail]; |
| 125 | int ret; |
| 126 | |
| 127 | queue->buf[queue->tail] = NULL; |
| 128 | as->var_values[VAR_B1 + out_id]++; |
| 129 | as->var_values[VAR_S1 + out_id] += buf->nb_samples; |
| 130 | if (buf->pts != AV_NOPTS_VALUE) |
| 131 | as->var_values[VAR_T1 + out_id] = |
| 132 | av_q2d(ctx->outputs[out_id]->time_base) * buf->pts; |
| 133 | as->var_values[VAR_T1 + out_id] += buf->nb_samples / |
| 134 | (double)ctx->inputs[out_id]->sample_rate; |
| 135 | ret = ff_filter_frame(ctx->outputs[out_id], buf); |
| 136 | queue->nb--; |
| 137 | queue->tail = (queue->tail + 1) % QUEUE_SIZE; |
| 138 | if (as->req[out_id]) |
| 139 | as->req[out_id]--; |
| 140 | return ret; |
| 141 | } |
| 142 | |
| 143 | static void send_next(AVFilterContext *ctx) |
| 144 | { |
| 145 | AStreamSyncContext *as = ctx->priv; |
| 146 | int i; |
| 147 | |
| 148 | while (1) { |
| 149 | if (!as->queue[as->next_out].nb) |
| 150 | break; |
| 151 | send_out(ctx, as->next_out); |
| 152 | if (!as->eof) |
| 153 | as->next_out = av_expr_eval(as->expr, as->var_values, NULL) >= 0; |
| 154 | } |
| 155 | for (i = 0; i < 2; i++) |
| 156 | if (as->queue[i].nb == QUEUE_SIZE) |
| 157 | send_out(ctx, i); |
| 158 | } |
| 159 | |
| 160 | static int request_frame(AVFilterLink *outlink) |
| 161 | { |
| 162 | AVFilterContext *ctx = outlink->src; |
| 163 | AStreamSyncContext *as = ctx->priv; |
| 164 | int id = outlink == ctx->outputs[1]; |
| 165 | |
| 166 | as->req[id]++; |
| 167 | while (as->req[id] && !(as->eof & (1 << id))) { |
| 168 | if (as->queue[as->next_out].nb) { |
| 169 | send_next(ctx); |
| 170 | } else { |
| 171 | as->eof |= 1 << as->next_out; |
| 172 | ff_request_frame(ctx->inputs[as->next_out]); |
| 173 | if (as->eof & (1 << as->next_out)) |
| 174 | as->next_out = !as->next_out; |
| 175 | } |
| 176 | } |
| 177 | return 0; |
| 178 | } |
| 179 | |
| 180 | static int filter_frame(AVFilterLink *inlink, AVFrame *insamples) |
| 181 | { |
| 182 | AVFilterContext *ctx = inlink->dst; |
| 183 | AStreamSyncContext *as = ctx->priv; |
| 184 | int id = inlink == ctx->inputs[1]; |
| 185 | |
| 186 | as->queue[id].buf[(as->queue[id].tail + as->queue[id].nb++) % QUEUE_SIZE] = |
| 187 | insamples; |
| 188 | as->eof &= ~(1 << id); |
| 189 | send_next(ctx); |
| 190 | return 0; |
| 191 | } |
| 192 | |
| 193 | static av_cold void uninit(AVFilterContext *ctx) |
| 194 | { |
| 195 | AStreamSyncContext *as = ctx->priv; |
| 196 | |
| 197 | av_expr_free(as->expr); |
| 198 | as->expr = NULL; |
| 199 | } |
| 200 | |
| 201 | static const AVFilterPad astreamsync_inputs[] = { |
| 202 | { |
| 203 | .name = "in1", |
| 204 | .type = AVMEDIA_TYPE_AUDIO, |
| 205 | .filter_frame = filter_frame, |
| 206 | },{ |
| 207 | .name = "in2", |
| 208 | .type = AVMEDIA_TYPE_AUDIO, |
| 209 | .filter_frame = filter_frame, |
| 210 | }, |
| 211 | { NULL } |
| 212 | }; |
| 213 | |
| 214 | static const AVFilterPad astreamsync_outputs[] = { |
| 215 | { |
| 216 | .name = "out1", |
| 217 | .type = AVMEDIA_TYPE_AUDIO, |
| 218 | .config_props = config_output, |
| 219 | .request_frame = request_frame, |
| 220 | },{ |
| 221 | .name = "out2", |
| 222 | .type = AVMEDIA_TYPE_AUDIO, |
| 223 | .config_props = config_output, |
| 224 | .request_frame = request_frame, |
| 225 | }, |
| 226 | { NULL } |
| 227 | }; |
| 228 | |
| 229 | AVFilter ff_af_astreamsync = { |
| 230 | .name = "astreamsync", |
| 231 | .description = NULL_IF_CONFIG_SMALL("Copy two streams of audio data " |
| 232 | "in a configurable order."), |
| 233 | .priv_size = sizeof(AStreamSyncContext), |
| 234 | .init = init, |
| 235 | .uninit = uninit, |
| 236 | .query_formats = query_formats, |
| 237 | .inputs = astreamsync_inputs, |
| 238 | .outputs = astreamsync_outputs, |
| 239 | .priv_class = &astreamsync_class, |
| 240 | }; |