[FFmpeg-devel] iSight camera support
Peter Ross
pross at xvid.org
Sun Mar 16 00:19:44 CET 2014
On Sat, Mar 15, 2014 at 07:34:47PM +0100, Thilo Borgmann wrote:
> Hi,
>
> Am 31.10.13 09:02, schrieb Stefano Sabatini:
> > On date Tuesday 2013-10-29 22:53:11 -0400, Vadim Kalinsky encoded:
> >>
>
> tested and improved with Stefano's latest remarks, except...
>
isight is the name given to the camera bundled with most mac computers.
can the qtkit framework access other capture devices? if this is the case,
i suggest using qtkit for AVInputFormat.name and --enable-qtkit in configure.
here is some more review inline.
[..]
> + at section isight
> +
> +iSight capture input device.
> +
> +The filename passed as input is the capture driver number.
> +
> + at example
> +ffmpeg -f isight -i 0 out.mpg
> + at end example
this comment is a inaccurate. the input filename is not used
by the device. i dont see any mention of AVFormatContext.filename.
in the patch.
> +
> @section jack
>
> JACK input device.
> diff --git a/libavdevice/Makefile b/libavdevice/Makefile
> index 7d07216..e64212e 100644
> --- a/libavdevice/Makefile
> +++ b/libavdevice/Makefile
> @@ -27,6 +27,7 @@ OBJS-$(CONFIG_FBDEV_INDEV) += fbdev_dec.o \
> OBJS-$(CONFIG_FBDEV_OUTDEV) += fbdev_enc.o \
> fbdev_common.o
> OBJS-$(CONFIG_IEC61883_INDEV) += iec61883.o
> +OBJS-$(CONFIG_ISIGHT_INDEV) += isight.o
> OBJS-$(CONFIG_JACK_INDEV) += jack_audio.o timefilter.o
> OBJS-$(CONFIG_LAVFI_INDEV) += lavfi.o
> OBJS-$(CONFIG_OPENAL_INDEV) += openal-dec.o
> @@ -47,6 +48,7 @@ OBJS-$(CONFIG_VFWCAP_INDEV) += vfwcap.o
> OBJS-$(CONFIG_X11GRAB_INDEV) += x11grab.o
> OBJS-$(CONFIG_XV_OUTDEV) += xv.o
>
> +
> # external libraries
> OBJS-$(CONFIG_LIBCDIO_INDEV) += libcdio.o
> OBJS-$(CONFIG_LIBDC1394_INDEV) += libdc1394.o
> diff --git a/libavdevice/alldevices.c b/libavdevice/alldevices.c
> index 005bbc8..fc412cc 100644
> --- a/libavdevice/alldevices.c
> +++ b/libavdevice/alldevices.c
> @@ -54,6 +54,7 @@ void avdevice_register_all(void)
> REGISTER_INDEV (DV1394, dv1394);
> REGISTER_INOUTDEV(FBDEV, fbdev);
> REGISTER_INDEV (IEC61883, iec61883);
> + REGISTER_INDEV (ISIGHT, isight);
> REGISTER_INDEV (JACK, jack);
> REGISTER_INDEV (LAVFI, lavfi);
> REGISTER_INDEV (OPENAL, openal);
> diff --git a/libavdevice/isight.m b/libavdevice/isight.m
> new file mode 100644
> index 0000000..65a42a0
> --- /dev/null
> +++ b/libavdevice/isight.m
> @@ -0,0 +1,306 @@
> +/*
> + * iSight capture device
> + * Copyright (c) 2013 Vadim Kalinsky <vadim at kalinsky.ru>
> + *
> + * 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
> + */
> +
> +#import <QTKit/QTkit.h>
> +#include <pthread.h>
> +
> +#include "libavutil/pixdesc.h"
> +#include "libavutil/opt.h"
> +#include "libavformat/internal.h"
> +#include "libavutil/internal.h"
> +#include "libavutil/time.h"
> +#include "avdevice.h"
> +
> +const int kISightTimeBase = 100;
use define or static const
> +
> +const AVRational kISightTimeBase_q = {
> + .num = 1,
> + .den = kISightTimeBase
> +};
use static const
> +
> +typedef struct
> +{
> + AVClass* class;
> +
> + float frame_rate;
> + int frames_captured;
> + int64_t first_pts;
> + pthread_mutex_t frame_lock;
> + pthread_cond_t frame_wait_cond;
> + id qt_delegate;
> +
> + QTCaptureSession* capture_session;
> + QTCaptureDecompressedVideoOutput* video_output;
> + CVImageBufferRef current_frame;
> +} CaptureContext;
> +
> +
surplus whitespace
> +static void lock_frames(CaptureContext* ctx)
> +{
> + pthread_mutex_lock(&ctx->frame_lock);
> +}
> +
> +static void unlock_frames(CaptureContext* ctx)
> +{
> + pthread_mutex_unlock(&ctx->frame_lock);
> +}
> +
> +
ditto
> +// FrameReciever class - delegate for QTCaptureSessiona
use doxygen comments
> + at interface FFMPEG_FrameReceiver : NSObject
> +{
> + CaptureContext* _context;
> +}
> +
> +- (id)initWithContext:(CaptureContext*)context;
> +
> +- (void)captureOutput:(QTCaptureOutput *)captureOutput
> + didOutputVideoFrame:(CVImageBufferRef)videoFrame
> + withSampleBuffer:(QTSampleBuffer *)sampleBuffer
> + fromConnection:(QTCaptureConnection *)connection;
> +
> + at end
> +
> + at implementation FFMPEG_FrameReceiver
> +
> +- (id)initWithContext:(CaptureContext*)context
> +{
> + if (self = [super init]) {
> + _context = context;
> + }
> + return self;
> +}
> +
> +- (void)captureOutput:(QTCaptureOutput *)captureOutput
> + didOutputVideoFrame:(CVImageBufferRef)videoFrame
> + withSampleBuffer:(QTSampleBuffer *)sampleBuffer
> + fromConnection:(QTCaptureConnection *)connection
> +{
> + lock_frames(_context);
> + if (_context->current_frame != nil) {
> + CVBufferRelease(_context->current_frame);
> + }
> +
> + _context->current_frame = CVBufferRetain(videoFrame);
> +
> + pthread_cond_signal(&_context->frame_wait_cond);
> +
> + unlock_frames(_context);
> +
> + ++_context->frames_captured;
> +}
> +
> + at end
> +
> +
surplus white space. if its important to seperate the
sections i recommend a comment.
> +static void destroy_context(CaptureContext* ctx)
> +{
> + [ctx->capture_session stopRunning];
> +
> + [ctx->capture_session release];
> + [ctx->video_output release];
> + [ctx->qt_delegate release];
> +
> + ctx->capture_session = NULL;
> + ctx->video_output = NULL;
> + ctx->qt_delegate = NULL;
> +
> + pthread_mutex_destroy(&ctx->frame_lock);
> + pthread_cond_destroy(&ctx->frame_wait_cond);
> +
> + if (ctx->current_frame)
> + CVBufferRelease(ctx->current_frame);
> +}
> +
> +static int isight_read_header(AVFormatContext *s)
> +{
> + NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
> +
> + CaptureContext* ctx = (CaptureContext*)s->priv_data;
> +
> + ctx->current_frame = NULL;
> + ctx->capture_session = NULL;
> + ctx->qt_delegate = NULL;
> + ctx->video_output = NULL;
> + ctx->frames_captured = 0;
s->priv_data is initialised to zero, so these are not required
> + ctx->first_pts = av_gettime();
> +
> + pthread_mutex_init(&ctx->frame_lock, NULL);
> + pthread_cond_init(&ctx->frame_wait_cond, NULL);
> +
> + // Find capture device
should be 'find defeault capture device'
> + QTCaptureDevice *video_device = [QTCaptureDevice defaultInputDeviceWithMediaType:QTMediaTypeMuxed];
> +
> + BOOL success = [video_device open:nil];
> +
> + // Video capture device not found, looking for QTMediaTypeVideo
> + if (!success) {
> + video_device = [QTCaptureDevice defaultInputDeviceWithMediaType:QTMediaTypeVideo];
> + success = [video_device open:nil];
> + }
> +
> + if (!success) {
> + av_log(s, AV_LOG_ERROR, "No QT capture device found\n");
> + goto fail;
> + }
you could put this second if (!success) block inside the earlier one.
potentially get rid of the success variable
if (![video_device open:nil]) {
video_device = [QTCaptureDevice defaultInputDeviceWithMediaType:QTMediaTypeVideo];
if (![video_device open:nil]) {
av_log(s, AV_LOG_ERROR, "No QT capture device found\n")
goto fail;
}
}
> +
> + NSString* dev_display_name = [video_device localizedDisplayName];
> + av_log (s, AV_LOG_DEBUG, "'%s' opened\n", [dev_display_name UTF8String]);
> +
> + // Initialize capture session
> + ctx->capture_session = [[QTCaptureSession alloc] init];
> +
> + QTCaptureDeviceInput* capture_dev_input = [[[QTCaptureDeviceInput alloc] initWithDevice:video_device] autorelease];
> + success = [ctx->capture_session addInput:capture_dev_input error:nil];
> + if (!success) {
> + av_log (s, AV_LOG_ERROR, "Failed to add QT capture device to session\n");
> + goto fail;
> + }
potentially get rid of the success variable
if (![ctx->capture_session addInput:capture_dev_input error:nil]) {
....
}
> +
> + // Attaching output
> + ctx->video_output = [[QTCaptureDecompressedVideoOutput alloc] init];
> +
> + NSDictionary *captureDictionary = [NSDictionary dictionaryWithObject:
> + [NSNumber numberWithUnsignedInt:kCVPixelFormatType_24RGB]
> + forKey:(id)kCVPixelBufferPixelFormatTypeKey];
add a FIXME for user-selected colorspace
(https://developer.apple.com/library/mac/documentation/QuartzCore/Reference/CVPixelFormatDescriptionRef/Reference/reference.html#//apple_ref/doc/constant_group/Pixel_Format_Types)
> +
> + [ctx->video_output setPixelBufferAttributes:captureDictionary];
> +
> + ctx->qt_delegate = [[FFMPEG_FrameReceiver alloc] initWithContext:ctx];
> + [ctx->video_output setDelegate:ctx->qt_delegate];
> + [ctx->video_output setAutomaticallyDropsLateVideoFrames:YES];
> + [ctx->video_output setMinimumVideoFrameInterval:1.0/ctx->frame_rate];
> +
> + success = [ctx->capture_session addOutput:ctx->video_output error:nil];
> +
> + if (!success) {
> + av_log (s, AV_LOG_ERROR, "can't add video output to capture session\n");
> + goto fail;
> + }
also potentially get rid of the success variable
> +
> +
> + [ctx->capture_session startRunning];
> +
> +
> + // Take stream info from the first frame.
some surplus whitespace.
> + while (ctx->frames_captured < 1) {
> + CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0.1, YES);
> + }
curly braces not needed
> +
> + lock_frames(ctx);
> +
> + size_t frame_width = CVPixelBufferGetWidth(ctx->current_frame);
> + size_t frame_height = CVPixelBufferGetHeight(ctx->current_frame);
you could call avformat_new_stream() earlier in the initialisation, and
set the stream->codec->width/height directly here, rather than using
a temporary variable.
> +
> + CVBufferRelease(ctx->current_frame);
> + ctx->current_frame = nil;
> +
> + unlock_frames(ctx);
> +
> + AVStream* stream = avformat_new_stream(s, NULL);
> + avpriv_set_pts_info(stream, 64, 1, kISightTimeBase);
> +
> + stream->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
> + stream->codec->codec_type = AVMEDIA_TYPE_VIDEO;
> + stream->codec->width = (int)frame_width;
> + stream->codec->height = (int)frame_height;
> + stream->codec->pix_fmt = AV_PIX_FMT_RGB24;
> +
> + s->start_time = 0;
doesnt this get initialised to zero by libavdevice?
> +
> + [pool release];
> +
> + return 0;
> +
> +fail:
> + [pool release];
> +
> + destroy_context(ctx);
> +
> + return AVERROR(EIO);
> +}
> +
> +static int isight_read_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> + CaptureContext* ctx = (CaptureContext*)s->priv_data;
> +
> + do {
> + lock_frames(ctx);
> +
> + if (ctx->current_frame != nil) {
> + CVPixelBufferLockBaseAddress(ctx->current_frame, 0);
according to https://developer.apple.com/library/mac/documentation/QuartzCore/Reference/CVPixelBufferRef/Reference/reference.html
CVPixelBufferLockBaseAddress is not needed for CVPixelBufferGetDataSize(),
only for CVPixelBufferGetBaseAddress (and CVPixelBufferGetBaseAddressOfPlane)
> + av_new_packet(pkt, (int)CVPixelBufferGetDataSize(ctx->current_frame));
check av_new_packet return value
> + pkt->pts = pkt->dts = av_rescale_q(av_gettime() - ctx->first_pts, AV_TIME_BASE_Q, kISightTimeBase_q);
> + pkt->stream_index = 0;
> + pkt->flags |= AV_PKT_FLAG_KEY;
> +
> + void* data = CVPixelBufferGetBaseAddress(ctx->current_frame);
> + memcpy(pkt->data, data, pkt->size);
> +
> + CVPixelBufferUnlockBaseAddress(ctx->current_frame, 0);
> + CVBufferRelease(ctx->current_frame);
> + ctx->current_frame = nil;
> + } else {
> + pkt->data = NULL;
> + }
> +
> + if (!pkt->data) {
> + pthread_cond_wait(&ctx->frame_wait_cond, &ctx->frame_lock);
> + }
these two blocks can be merged.
> +
> + unlock_frames(ctx);
> + } while (!pkt->data);
> +
> + return 0;
> +}
> +
> +static int isight_close(AVFormatContext *s)
> +{
> + CaptureContext* ctx = (CaptureContext*)s->priv_data;
> +
> + destroy_context(ctx);
> +
> + return 0;
> +}
> +
> +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 },
> + { NULL },
> +};
> +
> +static const AVClass isight_class = {
> + .class_name = "iSight camera",
> + .item_name = av_default_item_name,
> + .option = options,
> + .version = LIBAVUTIL_VERSION_INT,
> +};
> +
> +AVInputFormat ff_isight_demuxer = {
> + .name = "isight",
> + .long_name = NULL_IF_CONFIG_SMALL("MacBook/iMac embedded camera capture"),
> + .priv_data_size = sizeof(CaptureContext),
> + .read_header = isight_read_header,
> + .read_packet = isight_read_packet,
> + .read_close = isight_close,
> + .flags = AVFMT_NOFILE,
> + .priv_class = &isight_class,
> +};
> --
> 1.8.3.2
>
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> ffmpeg-devel at ffmpeg.org
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-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
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