From patchwork Sat Feb 13 18:47:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 8300641 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 01EB1C02AA for ; Sat, 13 Feb 2016 18:48:05 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2DC8B2042B for ; Sat, 13 Feb 2016 18:48:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 296CD2041E for ; Sat, 13 Feb 2016 18:47:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751236AbcBMSr5 (ORCPT ); Sat, 13 Feb 2016 13:47:57 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60983 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751083AbcBMSr4 (ORCPT ); Sat, 13 Feb 2016 13:47:56 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id 95FD78E258 for ; Sat, 13 Feb 2016 18:47:56 +0000 (UTC) Received: from shalem.localdomain.com (vpn1-4-73.ams2.redhat.com [10.36.4.73]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u1DIlejS011443; Sat, 13 Feb 2016 13:47:54 -0500 From: Hans de Goede To: Linux Media Mailing List Cc: Hans de Goede Subject: [PATCH tvtime 07/17] Add get_media_devices.c from xawtv Date: Sat, 13 Feb 2016 19:47:28 +0100 Message-Id: <1455389258-13470-7-git-send-email-hdegoede@redhat.com> In-Reply-To: <1455389258-13470-1-git-send-email-hdegoede@redhat.com> References: <1455389258-13470-1-git-send-email-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This will allow us to automatically detect the tv-card and the matching alsa capture device for the alsa digital loopback. Signed-off-by: Hans de Goede --- src/Makefile.am | 6 +- src/get_media_devices.c | 597 ++++++++++++++++++++++++++++++++++++++++++++++++ src/get_media_devices.h | 168 ++++++++++++++ 3 files changed, 769 insertions(+), 2 deletions(-) create mode 100644 src/get_media_devices.c create mode 100644 src/get_media_devices.h diff --git a/src/Makefile.am b/src/Makefile.am index bf05b90..931c65c 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -46,7 +46,8 @@ COMMON_SRCS = mixer.c videoinput.c rtctimer.c leetft.c osdtools.c tvtimeconf.c \ cpuinfo.h cpuinfo.c menu.c menu.h \ outputfilter.h outputfilter.c xmltv.h xmltv.c gettext.h tvtimeglyphs.h \ copyfunctions.h copyfunctions.c alsa_stream.c alsa_stream.h \ - epg.h epg.c mixer-oss.c $(ALSA_SRCS) + epg.h epg.c mixer-oss.c get_media_devices.c get_media_devices.h \ + $(ALSA_SRCS) if ARCH_X86 DSCALER_SRCS = ../plugins/dscalerapi.h \ @@ -94,7 +95,8 @@ tvtime_configure_SOURCES = utils.h utils.c tvtimeconf.h tvtimeconf.c \ tvtime_configure_CFLAGS = $(OPT_CFLAGS) $(XML2_FLAG) $(AM_CFLAGS) tvtime_configure_LDFLAGS = $(ZLIB_LIBS) $(XML2_LIBS) tvtime_scanner_SOURCES = utils.h utils.c videoinput.h videoinput.c \ - tvtimeconf.h tvtimeconf.c station.h station.c tvtime-scanner.c + tvtimeconf.h tvtimeconf.c station.h station.c tvtime-scanner.c \ + get_media_devices.c get_media_devices.h tvtime_scanner_CFLAGS = $(OPT_CFLAGS) $(XML2_FLAG) $(ALSA_CFLAGS) $(AM_CFLAGS) tvtime_scanner_LDFLAGS = $(ZLIB_LIBS) $(XML2_LIBS) $(ALSA_LIBS) diff --git a/src/get_media_devices.c b/src/get_media_devices.c new file mode 100644 index 0000000..619734e --- /dev/null +++ b/src/get_media_devices.c @@ -0,0 +1,597 @@ +/* + Copyright © 2011 by Mauro Carvalho Chehab + + The get_media_devices 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. + + The libv4l2util Library 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 the libv4l2util Library; if not, write to the Free + Software Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA + 02110-1335 USA. + */ + +#ifdef __linux__ /* This depends on sysfs, so it is linux only */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include "get_media_devices.h" + +#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) + +/** + * struct media_device_entry - Describes one device entry got via sysfs + * + * @device: sysfs name for a device. + * PCI devices are like: pci0000:00/0000:00:1b.0 + * USB devices are like: pci0000:00/0000:00:1d.7/usb1/1-8 + * @node: Device node, in sysfs or alsa hw identifier + * @device_type: Type of the device (V4L_*, DVB_*, SND_*) + */ +struct media_device_entry { + char *device; + char *node; + enum device_type type; + enum bus_type bus; + unsigned major, minor; /* Device major/minor */ +}; + +/** + * struct media_devices - Describes all devices found + * + * @device: sysfs name for a device. + * PCI devices are like: pci0000:00/0000:00:1b.0 + * USB devices are like: pci0000:00/0000:00:1d.7/usb1/1-8 + * @node: Device node, in sysfs or alsa hw identifier + * @device_type: Type of the device (V4L_*, DVB_*, SND_*) + */ +struct media_devices { + struct media_device_entry *md_entry; + unsigned int md_size; +}; + +typedef int (*fill_data_t)(struct media_device_entry *md); + +#define DEVICE_STR "devices" + +static void get_uevent_info(struct media_device_entry *md_ptr, char *dname) +{ + FILE *fd; + char file[PATH_MAX], *name, *p; + char s[1024]; + + snprintf(file, PATH_MAX, "%s/%s/uevent", dname, md_ptr->node); + fd = fopen(file, "r"); + if (!fd) + return; + while (fgets(s, sizeof(s), fd)) { + p = strtok(s, "="); + if (!p) + continue; + name = p; + p = strtok(NULL, "\n"); + if (!p) + continue; + if (!strcmp(name, "MAJOR")) + md_ptr->major = atol(p); + else if (!strcmp(name, "MINOR")) + md_ptr->minor = atol(p); + } + + fclose(fd); +} + +static enum bus_type get_bus(char *device) +{ + char file[PATH_MAX]; + char s[1024]; + FILE *f; + + if (!strcmp(device, "/sys/devices/virtual")) + return MEDIA_BUS_VIRTUAL; + + snprintf(file, PATH_MAX, "%s/modalias", device); + f = fopen(file, "r"); + if (!f) + return MEDIA_BUS_UNKNOWN; + if (!fgets(s, sizeof(s), f)) + return MEDIA_BUS_UNKNOWN; + fclose(f); + + if (!strncmp(s, "pci", 3)) + return MEDIA_BUS_PCI; + if (!strncmp(s, "usb", 3)) + return MEDIA_BUS_USB; + + return MEDIA_BUS_UNKNOWN; +} + +static int get_class(char *class, + struct media_device_entry **md, + unsigned int *md_size, + fill_data_t fill) +{ + DIR *dir; + struct dirent *entry; + char dname[PATH_MAX]; + char fname[PATH_MAX]; + char link[PATH_MAX]; + char virt_dev[60]; + int err = -2; + struct media_device_entry *md_ptr = NULL; + char *p, *device; + enum bus_type bus; + static int virtual = 0; + + snprintf(dname, PATH_MAX, "/sys/class/%s", class); + dir = opendir(dname); + if (!dir) { + return 0; + } + for (entry = readdir(dir); entry; entry = readdir(dir)) { + /* Skip . and .. */ + if (entry->d_name[0] == '.') + continue; + /* Canonicalize the device name */ + snprintf(fname, PATH_MAX, "%s/%s", dname, entry->d_name); + if (realpath(fname, link)) { + device = link; + + /* Remove the subsystem/class_name from the string */ + p = strstr(device, class); + if (!p) + continue; + *(p - 1) = '\0'; + + bus = get_bus(device); + + /* remove the /sys/devices/ from the name */ + device += 13; + + switch (bus) { + case MEDIA_BUS_PCI: + /* Remove the device function nr */ + p = strrchr(device, '.'); + if (!p) + continue; + *p = '\0'; + break; + case MEDIA_BUS_USB: + /* Remove USB interface from the path */ + p = strrchr(device, '/'); + if (!p) + continue; + /* In case we have a device where the driver + attaches directly to the usb device rather + then to an interface */ + if (!strchr(p, ':')) + break; + *p = '\0'; + break; + case MEDIA_BUS_VIRTUAL: + /* Don't group virtual devices */ + sprintf(virt_dev, "virtual%d", virtual++); + device = virt_dev; + break; + case MEDIA_BUS_UNKNOWN: + break; + } + + /* Add one more element to the devices struct */ + *md = realloc(*md, (*md_size + 1) * sizeof(*md_ptr)); + if (!*md) + goto error; + md_ptr = (*md) + *md_size; + (*md_size)++; + + /* Cleans previous data and fills it with device/node */ + memset(md_ptr, 0, sizeof(*md_ptr)); + md_ptr->type = UNKNOWN; + md_ptr->device = strdup(device); + md_ptr->node = strdup(entry->d_name); + + /* Retrieve major and minor information */ + get_uevent_info(md_ptr, dname); + + /* Used to identify the type of node */ + fill(md_ptr); + } + } + err = 0; +error: + closedir(dir); + return err; +} + +static int add_v4l_class(struct media_device_entry *md) +{ + if (strstr(md->node, "video")) + md->type = MEDIA_V4L_VIDEO; + else if (strstr(md->node, "vbi")) + md->type = MEDIA_V4L_VBI; + else if (strstr(md->node, "radio")) + md->type = MEDIA_V4L_RADIO; + else if (strstr(md->node, "v4l-subdev")) + md->type = MEDIA_V4L_SUBDEV; + + return 0; +} + +static int add_snd_class(struct media_device_entry *md) +{ + unsigned c = 65535, d = 65535; + char node[64]; + + if (strstr(md->node, "timer")) { + md->type = MEDIA_SND_TIMER; + return 0; + } else if (strstr(md->node, "seq")) { + md->type = MEDIA_SND_SEQ; + return 0; + } if (strstr(md->node, "card")) { + sscanf(md->node, "card%u", &c); + md->type = MEDIA_SND_CARD; + } else if (strstr(md->node, "hw")) { + sscanf(md->node, "hwC%uD%u", &c, &d); + md->type = MEDIA_SND_HW; + } else if (strstr(md->node, "control")) { + sscanf(md->node, "controlC%u", &c); + md->type = MEDIA_SND_CONTROL; + } else if (strstr(md->node, "pcm")) { + sscanf(md->node, "pcmC%uD%u", &c, &d); + if (md->node[strlen(md->node) - 1] == 'p') + md->type = MEDIA_SND_OUT; + else if (md->node[strlen(md->node) - 1] == 'c') + md->type = MEDIA_SND_CAP; + } + + if (c == 65535) + return 0; + + /* Reformat device to be useful for alsa userspace library */ + if (d == 65535) + snprintf(node, sizeof(node), "hw:%u", c); + else + snprintf(node, sizeof(node), "hw:%u,%u", c, d); + + free(md->node); + md->node = strdup(node); + + return 0; +} + +static int add_dvb_class(struct media_device_entry *md) +{ + if (strstr(md->node, "video")) + md->type = MEDIA_DVB_VIDEO; + if (strstr(md->node, "audio")) + md->type = MEDIA_DVB_AUDIO; + if (strstr(md->node, "sec")) + md->type = MEDIA_DVB_SEC; + if (strstr(md->node, "frontend")) + md->type = MEDIA_DVB_FRONTEND; + else if (strstr(md->node, "demux")) + md->type = MEDIA_DVB_DEMUX; + else if (strstr(md->node, "dvr")) + md->type = MEDIA_DVB_DVR; + else if (strstr(md->node, "net")) + md->type = MEDIA_DVB_NET; + else if (strstr(md->node, "ca")) + md->type = MEDIA_DVB_CA; + else if (strstr(md->node, "osd")) + md->type = MEDIA_DVB_OSD; + + return 0; +} + +static int sort_media_device_entry(const void *a, const void *b) +{ + const struct media_device_entry *md_a = a; + const struct media_device_entry *md_b = b; + int cmp; + + cmp = strcmp(md_a->device, md_b->device); + if (cmp) + return cmp; + cmp = (int)md_a->type - (int)md_b->type; + if (cmp) + return cmp; + + return strcmp(md_a->node, md_b->node); +} + + +/* Public functions */ + +void free_media_devices(void *opaque) +{ + struct media_devices *md = opaque; + struct media_device_entry *md_ptr = md->md_entry; + int i; + for (i = 0; i < md->md_size; i++) { + free(md_ptr->node); + free(md_ptr->device); + md_ptr++; + } + free(md->md_entry); + free(md); +} + +void *discover_media_devices(void) +{ + struct media_devices *md = NULL; + struct media_device_entry *md_entry = NULL; + + md = calloc(1, sizeof(*md)); + if (!md) + return NULL; + + md->md_size = 0; + if (get_class("video4linux", &md_entry, &md->md_size, add_v4l_class)) + goto error; + if (get_class("sound", &md_entry, &md->md_size, add_snd_class)) + goto error; + if (get_class("dvb", &md_entry, &md->md_size, add_dvb_class)) + goto error; + + /* There's no media device */ + if (!md_entry) + goto error; + + qsort(md_entry, md->md_size, sizeof(*md_entry), sort_media_device_entry); + + md->md_entry = md_entry; + + return md; + +error: + free_media_devices(md); + return NULL; +} + +const char *media_device_type(enum device_type type) +{ + switch(type) { + /* V4L nodes */ + case MEDIA_V4L_VIDEO: + return "video"; + case MEDIA_V4L_VBI: + return "vbi"; + case MEDIA_V4L_RADIO: + return "radio"; + case MEDIA_V4L_SUBDEV: + return "v4l subdevice"; + + /* DVB nodes */ + case MEDIA_DVB_VIDEO: + return "dvb video"; + case MEDIA_DVB_AUDIO: + return "dvb audio"; + case MEDIA_DVB_SEC: + return "dvb sec"; + case MEDIA_DVB_FRONTEND: + return "dvb frontend"; + case MEDIA_DVB_DEMUX: + return "dvb demux"; + case MEDIA_DVB_DVR: + return "dvb dvr"; + case MEDIA_DVB_NET: + return "dvb net"; + case MEDIA_DVB_CA: + return "dvb conditional access"; + case MEDIA_DVB_OSD: + return "dvb OSD"; + + /* Alsa nodes */ + case MEDIA_SND_CARD: + return "sound card"; + case MEDIA_SND_CAP: + return "pcm capture"; + case MEDIA_SND_OUT: + return "pcm output"; + case MEDIA_SND_CONTROL: + return "mixer"; + case MEDIA_SND_HW: + return "sound hardware"; + case MEDIA_SND_TIMER: + return "sound timer"; + case MEDIA_SND_SEQ: + return "sound sequencer"; + + default: + return "unknown"; + }; +} + +void display_media_devices(void *opaque) +{ + struct media_devices *md = opaque; + struct media_device_entry *md_ptr = md->md_entry; + int i; + char *prev = ""; + + for (i = 0; i < md->md_size; i++) { + if (strcmp(prev, md_ptr->device)) { + printf("\nDevice %s:\n\t", md_ptr->device); + prev = md_ptr->device; + } + printf("%s(%s, dev %i:%i) ", md_ptr->node, + media_device_type(md_ptr->type), + md_ptr->major, md_ptr->minor); + md_ptr++; + } + printf("\n"); +} + +const char *get_associated_device(void *opaque, + const char *last_seek, + const enum device_type desired_type, + const char *seek_device, + const enum device_type seek_type) +{ + struct media_devices *md = opaque; + struct media_device_entry *md_ptr = md->md_entry; + int i, found = 0; + char *prev, *p; + + if (seek_type != NONE && seek_device[0]) { + /* Get just the device name */ + p = strrchr(seek_device, '/'); + if (p) + seek_device = p + 1; + + /* Step 1: Find the seek node */ + for (i = 0; i < md->md_size; i++, md_ptr++) { + if (last_seek && md_ptr->type == seek_type && + !strcmp(md_ptr->node, last_seek)) { + found = 1; + continue; + } + if (last_seek && !found) + continue; + if (md_ptr->type == seek_type && + !strcmp(seek_device, md_ptr->node)) + break; + } + if (i == md->md_size) + return NULL; + i++; + prev = md_ptr->device; + md_ptr++; + /* Step 2: find the associated node */ + for (; i < md->md_size && !strcmp(prev, md_ptr->device); i++, md_ptr++) { + if (last_seek && md_ptr->type == seek_type && + !strcmp(md_ptr->node, last_seek)) { + found = 1; + continue; + } + if (last_seek && !found) + continue; + if (md_ptr->type == desired_type) + return md_ptr->node; + } + } else { + for (i = 0; i < md->md_size; i++, md_ptr++) { + if (last_seek && !strcmp(md_ptr->node, last_seek)) { + found = 1; + continue; + } + if (last_seek && !found) + continue; + if (md_ptr->type == desired_type) + return md_ptr->node; + } + } + + return NULL; +} + +const char *fget_associated_device(void *opaque, + const char *last_seek, + const enum device_type desired_type, + const int fd_seek_device, + const enum device_type seek_type) +{ + struct media_devices *md = opaque; + struct media_device_entry *md_ptr = md->md_entry; + struct stat f_status; + unsigned int dev_major, dev_minor; + int i, found = 0; + char *prev; + + if (fstat(fd_seek_device, &f_status)) { + perror("Can't get file status"); + return NULL; + } + if (!S_ISCHR(f_status.st_mode)) { + fprintf(stderr, "File descriptor is not a char device\n"); + return NULL; + } + dev_major = major(f_status.st_rdev); + dev_minor = minor(f_status.st_rdev); + + /* Step 1: Find the seek node */ + for (i = 0; i < md->md_size; i++, md_ptr++) { + if (last_seek && md_ptr->type == seek_type + && md_ptr->major == dev_major + && md_ptr->minor == dev_minor) { + found = 1; + continue; + } + if (last_seek && !found) + continue; + if (md_ptr->type == seek_type + && md_ptr->major == dev_major + && md_ptr->minor == dev_minor) + break; + } + if (i == md->md_size) + return NULL; + i++; + prev = md_ptr->device; + md_ptr++; + /* Step 2: find the associated node */ + for (; i < md->md_size && !strcmp(prev, md_ptr->device); i++, md_ptr++) { + if (last_seek && md_ptr->type == seek_type + && md_ptr->major == dev_major + && md_ptr->minor == dev_minor) { + found = 1; + continue; + } + if (last_seek && !found) + continue; + if (md_ptr->type == desired_type) + return md_ptr->node; + } + return NULL; +} + +const char *get_not_associated_device(void *opaque, + const char *last_seek, + const enum device_type desired_type, + const enum device_type not_desired_type) +{ + struct media_devices *md = opaque; + struct media_device_entry *md_ptr = md->md_entry; + int i, skip = 0, found = 0; + char *prev = "", *result = NULL; + + /* Step 1: Find a device without seek_type node */ + for (i = 0; i < md->md_size; i++, md_ptr++) { + if (last_seek && !strcmp(md_ptr->node, last_seek)) { + found = 1; + continue; + } + if (last_seek && !found) + continue; + if (strcmp(prev, md_ptr->device)) { + if (!skip && result) + break; + prev = md_ptr->device; + skip = 0; + result = NULL; + } + if (md_ptr->type == not_desired_type) + skip = 1; + else if (!skip && !result && md_ptr->type == desired_type) + result = md_ptr->node; + } + if (skip) + result = NULL; + + return result; +} + +#endif diff --git a/src/get_media_devices.h b/src/get_media_devices.h new file mode 100644 index 0000000..bfa697b --- /dev/null +++ b/src/get_media_devices.h @@ -0,0 +1,168 @@ +/* + Copyright © 2011 by Mauro Carvalho Chehab + + The get_media_devices 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. + + The libv4l2util Library 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 the libv4l2util Library; if not, write to the Free + Software Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA + 02110-1335 USA. + */ + +/* + * Version of the API + */ +#define GET_MEDIA_DEVICES_VERSION 0x0105 + +/** + * enum device_type - Enumerates the type for each device + * + * The device_type is used to sort the media devices array. + * So, the order is relevant. The first device should be + * MEDIA_V4L_VIDEO. + */ +enum device_type { + UNKNOWN = 65535, + NONE = 65534, + MEDIA_V4L_VIDEO = 0, + MEDIA_V4L_VBI, + MEDIA_V4L_RADIO, + MEDIA_V4L_SUBDEV, + + MEDIA_DVB_VIDEO = 100, + MEDIA_DVB_AUDIO, + MEDIA_DVB_SEC, + MEDIA_DVB_FRONTEND, + MEDIA_DVB_DEMUX, + MEDIA_DVB_DVR, + MEDIA_DVB_CA, + MEDIA_DVB_NET, + MEDIA_DVB_OSD, + + MEDIA_SND_CARD = 200, + MEDIA_SND_CAP, + MEDIA_SND_OUT, + MEDIA_SND_CONTROL, + MEDIA_SND_HW, + MEDIA_SND_TIMER, + MEDIA_SND_SEQ, + /* + * FIXME: not all alsa devices were mapped. missing things like + * midi, midiC%iD%i and timer interfaces + */ +}; + +enum bus_type { + MEDIA_BUS_UNKNOWN, + MEDIA_BUS_VIRTUAL, + MEDIA_BUS_PCI, + MEDIA_BUS_USB, +}; + +/** + * discover_media_devices() - Returns a list of the media devices + * @md_size: Returns the size of the media devices found + * + * This function reads the /sys/class nodes for V4L, DVB and sound, + * and returns an opaque desciptor that keeps a list of the devices. + * The fields on this list is opaque, as they can be changed on newer + * releases of this library. So, all access to it should be done via + * a function provided by the API. The devices are ordered by device, + * type and node. At return, md_size is updated. + */ +void *discover_media_devices(void); + +/** + * free_media_devices() - Frees the media devices array + * + * @opaque: media devices opaque descriptor + * + * As discover_media_devices() dynamically allocate space for the + * strings, feeing the list requires also to free those data. So, + * the safest and recommended way is to call this function. + */ +void free_media_devices(void *opaque); + +/** + * media_device_type() - returns a string with the name of a given type + * + * @type: media device type + */ +const char *media_device_type(const enum device_type type); + +/** + * display_media_devices() - prints a list of media devices + * + * @opaque: media devices opaque descriptor + */ +void display_media_devices(void *opaque); + +/** + * get_associated_device() - Return the next device associated with another one + * + * @opaque: media devices opaque descriptor + * @last_seek: last seek result. Use NULL to get the first result + * @desired_type: type of the desired device + * @seek_device: name of the device with you want to get an association. + *@ seek_type: type of the seek device. Using NONE produces the same + * result of using NULL for the seek_device. + * + * This function seeks inside the media_devices struct for the next device + * that it is associated with a seek parameter. + * It can be used to get an alsa device associated with a video device. If + * the seek_device is NULL or seek_type is NONE, it will just search for + * devices of the desired_type. + */ +const char *get_associated_device(void *opaque, + const char *last_seek, + const enum device_type desired_type, + const char *seek_device, + const enum device_type seek_type); + +/** + * fget_associated_device() - Return the next device associated with another one + * + * @opaque: media devices opaque descriptor + * @last_seek: last seek result. Use NULL to get the first result + * @desired_type: type of the desired device + * @fd_seek_device: file handler for the device where the association will + be made + *@ seek_type: type of the seek device. Using NONE produces the same + * result of using NULL for the seek_device. + * + * This function seeks inside the media_devices struct for the next device + * that it is associated with a seek parameter. + * It can be used to get an alsa device associated with an open file descriptor + */ +const char *fget_associated_device(void *opaque, + const char *last_seek, + const enum device_type desired_type, + const int fd_seek_device, + const enum device_type seek_type); + +/** + * get_not_associated_device() - Return the next device not associated with + * an specific device type. + * + * @opaque: media devices opaque descriptor + * @last_seek: last seek result. Use NULL to get the first result + * @desired_type: type of the desired device + * @not_desired_type: type of the seek device + * + * This function seeks inside the media_devices struct for the next physical + * device that doesn't support a non_desired type. + * This method is useful for example to return the audio devices that are + * provided by the motherboard. + */ +const char *get_not_associated_device(void *opaque, + const char *last_seek, + const enum device_type desired_type, + const enum device_type not_desired_type);