avfilter: add streamselect and astreamselect filter

Signed-off-by: Clément Bœsch <u@pkh.me>
Signed-off-by: Paul B Mahol <onemda@gmail.com>

1 files changed, 353 insertions, 0 deletions

diff --git a/libavfilter/f_streamselect.c b/libavfilter/f_streamselect.c
new file mode 100644
index 0000000000..db46c997ed
--- /dev/null
+++ b/libavfilter/f_streamselect.c
@@ -0,0 +1,353 @@
+/*
+ * 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
+ */
+
+#include "libavutil/avstring.h"
+#include "libavutil/internal.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "audio.h"
+#include "formats.h"
+#include "framesync.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct StreamSelectContext {
+    const AVClass *class;
+    int nb_inputs;
+    char *map_str;
+    int *map;
+    int nb_map;
+    int is_audio;
+    int64_t *last_pts;
+    AVFrame **frames;
+    FFFrameSync fs;
+} StreamSelectContext;
+
+#define OFFSET(x) offsetof(StreamSelectContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
+static const AVOption streamselect_options[] = {
+    { "inputs",  "number of input streams",           OFFSET(nb_inputs),  AV_OPT_TYPE_INT,    {.i64=2},    2, INT_MAX,  .flags=FLAGS },
+    { "map",     "input indexes to remap to outputs", OFFSET(map_str),    AV_OPT_TYPE_STRING, {.str=NULL},              .flags=FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(streamselect);
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    StreamSelectContext *s = inlink->dst->priv;
+    return ff_framesync_filter_frame(&s->fs, inlink, in);
+}
+
+static int process_frame(FFFrameSync *fs)
+{
+    AVFilterContext *ctx = fs->parent;
+    StreamSelectContext *s = fs->opaque;
+    AVFrame **in = s->frames;
+    int i, j, ret = 0;
+
+    for (i = 0; i < ctx->nb_inputs; i++) {
+        if ((ret = ff_framesync_get_frame(&s->fs, i, &in[i], 0)) < 0)
+            return ret;
+    }
+
+    for (j = 0; j < ctx->nb_inputs; j++) {
+        for (i = 0; i < s->nb_map; i++) {
+            if (s->map[i] == j) {
+                AVFrame *out;
+
+                if (s->is_audio && s->last_pts[j] == in[j]->pts &&
+                    ctx->outputs[i]->frame_count > 0)
+                    continue;
+                out = av_frame_clone(in[j]);
+                if (!out)
+                    return AVERROR(ENOMEM);
+
+                out->pts = av_rescale_q(s->fs.pts, s->fs.time_base, ctx->outputs[i]->time_base);
+                s->last_pts[j] = in[j]->pts;
+                ret = ff_filter_frame(ctx->outputs[i], out);
+                if (ret < 0)
+                    return ret;
+            }
+        }
+    }
+
+    return ret;
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+    StreamSelectContext *s = outlink->src->priv;
+    return ff_framesync_request_frame(&s->fs, outlink);
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    StreamSelectContext *s = ctx->priv;
+    const int outlink_idx = FF_OUTLINK_IDX(outlink);
+    const int inlink_idx  = s->map[outlink_idx];
+    AVFilterLink *inlink = ctx->inputs[inlink_idx];
+    FFFrameSyncIn *in;
+    int i, ret;
+
+    av_log(ctx, AV_LOG_VERBOSE, "config output link %d "
+           "with settings from input link %d\n",
+           outlink_idx, inlink_idx);
+
+    switch (outlink->type) {
+    case AVMEDIA_TYPE_VIDEO:
+        outlink->w = inlink->w;
+        outlink->h = inlink->h;
+        outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
+        outlink->frame_rate = inlink->frame_rate;
+        break;
+    case AVMEDIA_TYPE_AUDIO:
+        outlink->sample_rate    = inlink->sample_rate;
+        outlink->channels       = inlink->channels;
+        outlink->channel_layout = inlink->channel_layout;
+        break;
+    }
+
+    outlink->time_base = inlink->time_base;
+    outlink->format = inlink->format;
+
+    if (s->fs.opaque == s)
+        return 0;
+
+    if ((ret = ff_framesync_init(&s->fs, ctx, ctx->nb_inputs)) < 0)
+        return ret;
+
+    in = s->fs.in;
+    s->fs.opaque = s;
+    s->fs.on_event = process_frame;
+
+    for (i = 0; i < ctx->nb_inputs; i++) {
+        in[i].time_base = ctx->inputs[i]->time_base;
+        in[i].sync      = 1;
+        in[i].before    = EXT_STOP;
+        in[i].after     = EXT_STOP;
+    }
+
+    s->frames = av_calloc(ctx->nb_inputs, sizeof(*s->frames));
+    if (!s->frames)
+        return AVERROR(ENOMEM);
+
+    return ff_framesync_configure(&s->fs);
+}
+
+static int parse_definition(AVFilterContext *ctx, int nb_pads, void *filter_frame, int is_audio)
+{
+    const int is_input = !!filter_frame;
+    const char *padtype = is_input ? "in" : "out";
+    int i = 0, ret = 0;
+
+    for (i = 0; i < nb_pads; i++) {
+        AVFilterPad pad = { 0 };
+
+        pad.type = is_audio ? AVMEDIA_TYPE_AUDIO : AVMEDIA_TYPE_VIDEO;
+
+        pad.name = av_asprintf("%sput%d", padtype, i);
+        if (!pad.name)
+            return AVERROR(ENOMEM);
+
+        av_log(ctx, AV_LOG_DEBUG, "Add %s pad %s\n", padtype, pad.name);
+
+        if (is_input) {
+            pad.filter_frame = filter_frame;
+            ret = ff_insert_inpad(ctx, i, &pad);
+        } else {
+            pad.config_props  = config_output;
+            pad.request_frame = request_frame;
+            ret = ff_insert_outpad(ctx, i, &pad);
+        }
+
+        if (ret < 0) {
+            av_freep(&pad.name);
+            return ret;
+        }
+    }
+
+    return 0;
+}
+
+static int parse_mapping(AVFilterContext *ctx, const char *map)
+{
+    StreamSelectContext *s = ctx->priv;
+    int *new_map;
+    int new_nb_map = 0;
+
+    if (!map) {
+        av_log(ctx, AV_LOG_ERROR, "mapping definition is not set\n");
+        return AVERROR(EINVAL);
+    }
+
+    new_map = av_calloc(s->nb_inputs, sizeof(*new_map));
+    if (!new_map)
+        return AVERROR(ENOMEM);
+
+    while (1) {
+        char *p;
+        const int n = strtol(map, &p, 0);
+
+        av_log(ctx, AV_LOG_DEBUG, "n=%d map=%p p=%p\n", n, map, p);
+
+        if (map == p)
+            break;
+        map = p;
+
+        if (new_nb_map >= s->nb_inputs) {
+            av_log(ctx, AV_LOG_ERROR, "Unable to map more than the %d "
+                   "input pads available\n", s->nb_inputs);
+            av_free(new_map);
+            return AVERROR(EINVAL);
+        }
+
+        if (n < 0 || n >= ctx->nb_inputs) {
+            av_log(ctx, AV_LOG_ERROR, "Input stream index %d doesn't exist "
+                   "(there is only %d input streams defined)\n",
+                   n, s->nb_inputs);
+            av_free(new_map);
+            return AVERROR(EINVAL);
+        }
+
+        av_log(ctx, AV_LOG_VERBOSE, "Map input stream %d to output stream %d\n", n, new_nb_map);
+        new_map[new_nb_map++] = n;
+    }
+
+    if (!new_nb_map) {
+        av_log(ctx, AV_LOG_ERROR, "invalid mapping\n");
+        av_free(new_map);
+        return AVERROR(EINVAL);
+    }
+
+    av_freep(&s->map);
+    s->map = new_map;
+    s->nb_map = new_nb_map;
+
+    av_log(ctx, AV_LOG_VERBOSE, "%d map set\n", s->nb_map);
+
+    return 0;
+}
+
+static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
+                           char *res, int res_len, int flags)
+{
+    if (!strcmp(cmd, "map")) {
+        int ret = parse_mapping(ctx, args);
+
+        if (ret < 0)
+            return ret;
+        return avfilter_config_links(ctx);
+    }
+    return AVERROR(ENOSYS);
+}
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    StreamSelectContext *s = ctx->priv;
+    int ret, nb_outputs = 0;
+    char *map = s->map_str;
+
+    if (!strcmp(ctx->filter->name, "astreamselect"))
+        s->is_audio = 1;
+
+    for (;;) {
+        char *p;
+
+        strtol(map, &p, 0);
+        if (map == p)
+            break;
+        nb_outputs++;
+        map = p;
+    }
+
+    s->last_pts = av_calloc(s->nb_inputs, sizeof(*s->last_pts));
+    if (!s->last_pts)
+        return AVERROR(ENOMEM);
+
+    if ((ret = parse_definition(ctx, s->nb_inputs, filter_frame, s->is_audio)) < 0 ||
+        (ret = parse_definition(ctx, nb_outputs, NULL, s->is_audio)) < 0)
+        return ret;
+
+    av_log(ctx, AV_LOG_DEBUG, "Configured with %d inpad and %d outpad\n",
+           ctx->nb_inputs, ctx->nb_outputs);
+
+    return parse_mapping(ctx, s->map_str);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    StreamSelectContext *s = ctx->priv;
+
+    av_freep(&s->last_pts);
+    av_freep(&s->map);
+    av_freep(&s->frames);
+    ff_framesync_uninit(&s->fs);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    AVFilterFormats *formats, *rates = NULL;
+    AVFilterChannelLayouts *layouts = NULL;
+    int ret, i;
+
+    for (i = 0; i < ctx->nb_inputs; i++) {
+        formats = ff_all_formats(ctx->inputs[i]->type);
+        if ((ret = ff_set_common_formats(ctx, formats)) < 0)
+            return ret;
+
+        if (ctx->inputs[i]->type == AVMEDIA_TYPE_AUDIO) {
+            rates = ff_all_samplerates();
+            if ((ret = ff_set_common_samplerates(ctx, rates)) < 0)
+                return ret;
+            layouts = ff_all_channel_counts();
+            if ((ret = ff_set_common_channel_layouts(ctx, layouts)) < 0)
+                return ret;
+        }
+    }
+
+    return 0;
+}
+
+AVFilter ff_vf_streamselect = {
+    .name            = "streamselect",
+    .description     = NULL_IF_CONFIG_SMALL("Select video streams"),
+    .init            = init,
+    .query_formats   = query_formats,
+    .process_command = process_command,
+    .uninit          = uninit,
+    .priv_size       = sizeof(StreamSelectContext),
+    .priv_class      = &streamselect_class,
+    .flags           = AVFILTER_FLAG_DYNAMIC_INPUTS | AVFILTER_FLAG_DYNAMIC_OUTPUTS,
+};
+
+#define astreamselect_options streamselect_options
+AVFILTER_DEFINE_CLASS(astreamselect);
+
+AVFilter ff_af_astreamselect = {
+    .name            = "astreamselect",
+    .description     = NULL_IF_CONFIG_SMALL("Select audio streams"),
+    .init            = init,
+    .query_formats   = query_formats,
+    .process_command = process_command,
+    .uninit          = uninit,
+    .priv_size       = sizeof(StreamSelectContext),
+    .priv_class      = &astreamselect_class,
+    .flags           = AVFILTER_FLAG_DYNAMIC_INPUTS | AVFILTER_FLAG_DYNAMIC_OUTPUTS,
+};