[vlc-devel] [PATCH 2/4] ytdl: stream filter module for YoutubeDL

[Rémi Denis-Courmont]

This passes every HTTP(S) URL through YoutubeDL to extract playlists
or media, unless the underlying stream is already a playlist.
---
 NEWS                              |   1 +
 modules/stream_filter/Makefile.am |   7 +
 modules/stream_filter/ytdl.c      | 204 ++++++++++++++++++++++++++++++
 po/POTFILES.in                    |   1 +
 4 files changed, 213 insertions(+)
 create mode 100644 modules/stream_filter/ytdl.c

diff --git a/NEWS b/NEWS
index 9af6a77b8f..7eb1a72567 100644
--- a/NEWS
+++ b/NEWS
@@ -65,6 +65,7 @@ Access:
  * Audio CD data tracks are now correctly detected and skipped
  * Deprecates Audio CD CDDB lookups in favor of more accurate Musicbrainz
  * Improved CD-TEXT and added Shift-JIS encoding support
+ * Support for YoutubeDL (where available).
 
 Access output:
  * Added support for the RIST (Reliable Internet Stream Transport) Protocol
diff --git a/modules/stream_filter/Makefile.am b/modules/stream_filter/Makefile.am
index 11f86a4a63..164c30bec6 100644
--- a/modules/stream_filter/Makefile.am
+++ b/modules/stream_filter/Makefile.am
@@ -51,3 +51,10 @@ stream_filter_LTLIBRARIES += libadf_plugin.la
 
 libskiptags_plugin_la_SOURCES = stream_filter/skiptags.c
 stream_filter_LTLIBRARIES += libskiptags_plugin.la
+
+libytdl_plugin_la_SOURCES = stream_filter/ytdl.c
+if !HAVE_WIN32
+if !HAVE_ANDROID
+stream_filter_LTLIBRARIES += libytdl_plugin.la
+endif
+endif
diff --git a/modules/stream_filter/ytdl.c b/modules/stream_filter/ytdl.c
new file mode 100644
index 0000000000..6da83e0c08
--- /dev/null
+++ b/modules/stream_filter/ytdl.c
@@ -0,0 +1,204 @@
+/*****************************************************************************
+ * ytdl.c:
+ *****************************************************************************
+ * Copyright (C) 2019-2020 Rémi Denis-Courmont
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdlib.h>
+
+#include <vlc_common.h>
+#include <vlc_stream.h>
+#include <vlc_fs.h>
+#include <vlc_input_item.h>
+#include <vlc_interrupt.h>
+#include <vlc_plugin.h>
+#include <vlc_spawn.h>
+
+
+struct ytdl_playlist {
+    pid_t pid;
+    int fd;
+    int first_byte;
+};
+
+static size_t readall(int fd, void *buf, size_t len)
+{
+    size_t total = 0;
+
+    while (len > 0 && !vlc_killed()) {
+        ssize_t val = vlc_read_i11e(fd, buf, len);
+
+        if (val == 0)
+            break; /* EOS */
+
+        if (val < 0) {
+            if (errno != EINTR)
+                break; /* fatal error */
+            continue;
+        }
+
+        buf = (char *)buf + val;
+        len -= val;
+        total += val;
+    }
+
+    return total;
+}
+
+static ssize_t Read(stream_t *s, void *buf, size_t len)
+{
+    struct ytdl_playlist *sys = s->p_sys;
+
+    if (unlikely(sys->first_byte != EOF)) {
+        /* Relay the first byte that was dequeued while probing. */
+        if (likely(len > 0)) {
+            *(unsigned char *)buf = sys->first_byte;
+            sys->first_byte = EOF;
+        }
+
+        return len > 0;
+    }
+
+    ssize_t val = vlc_read_i11e(sys->fd, buf, len);
+
+    if (val < 0) {
+        if (errno == EINTR || errno == EAGAIN)
+            return -1;
+
+        msg_Err(s, "read error: %s", vlc_strerror_c(errno));
+        val = 0;
+    }
+
+    return val;
+}
+
+static int Control(stream_t *s, int query, va_list args)
+{
+    switch (query)
+    {
+        case STREAM_CAN_SEEK:
+        case STREAM_CAN_FASTSEEK:
+        case STREAM_CAN_PAUSE:
+        case STREAM_CAN_CONTROL_PACE:
+            *va_arg(args, bool *) = false;
+            break;
+
+        case STREAM_GET_TYPE:
+            *va_arg(args, int *) = ITEM_TYPE_PLAYLIST;
+            break;
+
+        case STREAM_GET_PTS_DELAY:
+            *va_arg(args, vlc_tick_t *) =
+                 VLC_TICK_FROM_MS(var_InheritInteger(s, "network-caching"));
+            break;
+
+        default:
+            return VLC_EGENERIC;
+
+    }
+
+    return VLC_SUCCESS;
+}
+
+static void Close(vlc_object_t *obj)
+{
+    stream_t *s = (stream_t *)obj;
+    struct ytdl_playlist *sys = s->p_sys;
+
+    msg_Dbg(s, "terminating PID %u", (unsigned)sys->pid);
+    kill(sys->pid, SIGTERM);
+    vlc_close(sys->fd);
+    vlc_waitpid(sys->pid);
+}
+
+static int OpenFilter(vlc_object_t *obj)
+{
+    stream_t *s = (stream_t *)obj;
+    ssize_t val;
+
+    if (s->s->pf_readdir != NULL || s->psz_url == NULL)
+        return VLC_EGENERIC;
+   if (strncasecmp(s->psz_url, "http:", 5)
+    && strncasecmp(s->psz_url, "https:", 6))
+       return VLC_EGENERIC;
+    if (!var_InheritBool(s, "ytdl"))
+        return VLC_EGENERIC;
+
+    struct ytdl_playlist *sys = vlc_obj_malloc(obj, sizeof (*sys));
+    if (unlikely(sys == NULL))
+        return VLC_EGENERIC;
+
+    char *path = config_GetSysPath(VLC_PKG_DATA_DIR, "ytdl-extract.py");
+    if (unlikely(path == NULL))
+        return VLC_EGENERIC;
+
+    int fds[2];
+
+    if (vlc_pipe(fds)) {
+        free(path);
+        return VLC_EGENERIC;
+    }
+
+    s->p_sys = sys;
+    sys->fd = fds[0];
+
+    int fdv[] = { -1, fds[1], 2, -1 };
+    const char *argv[] = { path, s->psz_url, NULL };
+
+    val = vlc_spawn(&sys->pid, path, fdv, argv);
+    vlc_close(fds[1]);
+
+    if (val) {
+        msg_Dbg(obj, "cannot start %s: %s", path, vlc_strerror_c(val));
+        free(path);
+        vlc_close(fds[0]);
+        return VLC_EGENERIC;
+    }
+
+    free(path);
+
+    unsigned char first_byte;
+    if (readall(sys->fd, &first_byte, 1) <= 0) {
+        /* Location not handled */
+        msg_Dbg(s, "cannot extract infos");
+        Close(obj);
+        return VLC_EGENERIC;
+    }
+
+    sys->first_byte = first_byte;
+    s->pf_read = Read;
+    s->pf_control = Control;
+    return VLC_SUCCESS;
+}
+
+vlc_module_begin()
+    set_shortname("YT-DL")
+    set_description("YoutubeDL")
+    set_category(CAT_INPUT)
+    set_subcategory(SUBCAT_INPUT_STREAM_FILTER)
+    set_capability("stream_filter", 305)
+    set_callbacks(OpenFilter, Close)
+    add_bool("ytdl", true, N_("Enable YT-DL"), N_("Enable YT-DL"), true)
+        change_safe()
+vlc_module_end()
diff --git a/po/POTFILES.in b/po/POTFILES.in
index d5ce933408..7b9af4bbc8 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -1151,6 +1151,7 @@ modules/stream_filter/inflate.c
 modules/stream_filter/prefetch.c
 modules/stream_filter/record.c
 modules/stream_filter/skiptags.c
+modules/stream_filter/ytdl.c
 modules/stream_out/autodel.c
 modules/stream_out/bridge.c
 modules/stream_out/chromaprint.c
-- 
2.28.0