[FFmpeg-devel] [PATCH] lavd/qtkit: Support choosing the input device by index or by name.
Thilo Borgmann
thilo.borgmann at mail.de
Mon Mar 31 00:29:54 CEST 2014
Am 30.03.14 21:54, schrieb Lukasz Marek:
> On 30.03.2014 21:17, Thilo Borgmann wrote:
>>> From a44489698c7237988817a63e55058e0d49b120dc Mon Sep 17 00:00:00 2001
>> From: Thilo Borgmann<thilo.borgmann at mail.de>
>> Date: Sun, 30 Mar 2014 21:13:04 +0200
>> Subject: [PATCH 1/2] lavd/qtkit: Support choosing the input device by index or
>> by name.
>>
>> ---
>> doc/indevs.texi | 8 +++++++-
>> libavdevice/qtkit.m | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++--
>> 2 files changed, 59 insertions(+), 3 deletions(-)
>>[...]
>> +
>> + // check for device index given in filename
>> + if (ctx->video_device_index == -1) {
>> + sscanf(s->filename, "%d", &ctx->video_device_index);
>> + }
>
> I'm not sure it is required. It can possibly lead to scan a random number that
> is a part of device name.
I wouldn't like to drop this convenience functionality except for a real
problem. However, checking for invalid numbers should be more robust now.
>> + if (ctx->video_device_index != -1) {
>> + NSArray *devices = [QTCaptureDevice
>> inputDevicesWithMediaType:QTMediaTypeVideo];
>> +
>> + if (ctx->video_device_index >= [devices count]) {
>> + av_log(ctx, AV_LOG_ERROR, "Invalid device index\n");
>> + goto fail;
>> + }
>> +
>> + video_device = [devices objectAtIndex:ctx->video_device_index];
>> + } else if (strncmp(s->filename, "", 1)) {
>
> Many devices uses string "default" for this reason, not empty string. Be free to
> ignore this, but this would make it more consistent with other devices.
Nice hint - "default" added.
>> [...]
>
> You may also consider implementing .get_device_list callback to obtain device
> list programmatically (as another patch).
Hm. If anyone convinces me of a benifit in that, I could do it.
Updated patch attached.
Thanks,
Thilo
-------------- next part --------------
>From b0d528be5d0f08b157aec1b4c92e41474fa69689 Mon Sep 17 00:00:00 2001
From: Thilo Borgmann <thilo.borgmann at mail.de>
Date: Mon, 31 Mar 2014 00:21:22 +0200
Subject: [PATCH] lavd/qtkit: Support choosing the input device by index or by
name.
---
doc/indevs.texi | 19 +++++++++++++++++-
libavdevice/qtkit.m | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 71 insertions(+), 3 deletions(-)
diff --git a/doc/indevs.texi b/doc/indevs.texi
index 68905ae..2de724d 100644
--- a/doc/indevs.texi
+++ b/doc/indevs.texi
@@ -535,12 +535,29 @@ ffmpeg -f pulse -i default /tmp/pulse.wav
QTKit input device.
-The filename passed as input is unused. The default device will be chosen.
+The filename passed as input is parsed to contain either a device name or index.
+The device index can also be given by using -video_device_index.
+A given device index will override any given device name.
+If the desired device consists of numbers only, use -video_device_index to identify it.
+The default device will be chosen if an empty string or the device name "default" is given.
+The available devices can be enumerated by using -list_devices.
@example
ffmpeg -f qtkit -i "0" out.mpg
@end example
+ at example
+ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
+ at end example
+
+ at example
+ffmpeg -f qtkit -i "default" out.mpg
+ at end example
+
+ at example
+ffmpeg -f qtkit -list_devices true -i ""
+ at end example
+
@section sndio
sndio input device.
diff --git a/libavdevice/qtkit.m b/libavdevice/qtkit.m
index 038ce02..ddb78e4 100644
--- a/libavdevice/qtkit.m
+++ b/libavdevice/qtkit.m
@@ -53,6 +53,9 @@ typedef struct
pthread_cond_t frame_wait_cond;
id qt_delegate;
+ int list_devices;
+ int video_device_index;
+
QTCaptureSession* capture_session;
QTCaptureDecompressedVideoOutput* video_output;
CVImageBufferRef current_frame;
@@ -145,8 +148,52 @@ static int qtkit_read_header(AVFormatContext *s)
pthread_mutex_init(&ctx->frame_lock, NULL);
pthread_cond_init(&ctx->frame_wait_cond, NULL);
- // Find default capture device
- QTCaptureDevice *video_device = [QTCaptureDevice defaultInputDeviceWithMediaType:QTMediaTypeMuxed];
+ // List devices if requested
+ if (ctx->list_devices) {
+ av_log(ctx, AV_LOG_INFO, "QTKit video devices:\n");
+ NSArray *devices = [QTCaptureDevice inputDevicesWithMediaType:QTMediaTypeVideo];
+ for (QTCaptureDevice *device in devices) {
+ char *name = [[device localizedDisplayName] UTF8String];
+ int index = [devices indexOfObject:device];
+ av_log(ctx, AV_LOG_INFO, "[%d] %s\n", index, name);
+ }
+ goto fail;
+ }
+
+ // Find capture device
+ QTCaptureDevice *video_device = nil;
+
+ // check for device index given in filename
+ if (ctx->video_device_index == -1) {
+ sscanf(s->filename, "%d", &ctx->video_device_index);
+ }
+
+ if (ctx->video_device_index >= 0) {
+ NSArray *devices = [QTCaptureDevice inputDevicesWithMediaType:QTMediaTypeVideo];
+
+ if (ctx->video_device_index >= [devices count]) {
+ av_log(ctx, AV_LOG_ERROR, "Invalid device index\n");
+ goto fail;
+ }
+
+ video_device = [devices objectAtIndex:ctx->video_device_index];
+ } else if (strncmp(s->filename, "", 1) &&
+ strncmp(s->filename, "default", 7)) {
+ NSArray *devices = [QTCaptureDevice inputDevicesWithMediaType:QTMediaTypeVideo];
+
+ for (QTCaptureDevice *device in devices) {
+ if (!strncmp(s->filename, [[device localizedDisplayName] UTF8String], strlen(s->filename))) {
+ video_device = device;
+ break;
+ }
+ }
+ if (!video_device) {
+ av_log(ctx, AV_LOG_ERROR, "Video device not found\n");
+ goto fail;
+ }
+ } else {
+ video_device = [QTCaptureDevice defaultInputDeviceWithMediaType:QTMediaTypeMuxed];
+ }
BOOL success = [video_device open:nil];
@@ -284,6 +331,10 @@ static int qtkit_close(AVFormatContext *s)
static const AVOption options[] = {
{ "frame_rate", "set frame rate", offsetof(CaptureContext, frame_rate), AV_OPT_TYPE_FLOAT, { .dbl = 30.0 }, 0.1, 30.0, AV_OPT_TYPE_VIDEO_RATE, NULL },
+ { "list_devices", "list available devices", offsetof(CaptureContext, list_devices), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM, "list_devices" },
+ { "true", "", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "list_devices" },
+ { "false", "", 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "list_devices" },
+ { "video_device_index", "select video device by index for devices with same name (starts at 0)", offsetof(CaptureContext, video_device_index), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
{ NULL },
};
--
1.8.3.2
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