@@ -26,7 +26,7 @@
*/
#import <AVFoundation/AVFoundation.h>
-#include <pthread.h>
+#import <CoreMedia/CoreMedia.h>
#include "libavutil/channel_layout.h"
#include "libavutil/pixdesc.h"
@@ -39,6 +39,11 @@
#include "libavutil/imgutils.h"
#include "avdevice.h"
+#define av_log_avfoundation_error(str, err) \
+ av_log(s, AV_LOG_ERROR, "Avfoundation: %s, %s\n", str, \
+ [[[NSError errorWithDomain:NSOSStatusErrorDomain code:err userInfo:nil] localizedDescription] UTF8String] \
+ )
+
static const int avf_time_base = 1000000;
static const AVRational avf_time_base_q = {
@@ -80,13 +85,12 @@
{ AV_PIX_FMT_NONE, 0 }
};
+#define MAX_QUEUED_FRAMES 10
+
typedef struct
{
AVClass* class;
- int frames_captured;
- int audio_frames_captured;
- pthread_mutex_t frame_lock;
id avf_delegate;
id avf_audio_delegate;
@@ -122,8 +126,8 @@
AVCaptureSession *capture_session;
AVCaptureVideoDataOutput *video_output;
AVCaptureAudioDataOutput *audio_output;
- CMSampleBufferRef current_frame;
- CMSampleBufferRef current_audio_frame;
+ CMSimpleQueueRef audio_frames_queue;
+ CMSimpleQueueRef video_frames_queue;
AVCaptureDevice *observed_device;
#if !TARGET_OS_IPHONE && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1070
@@ -132,16 +136,6 @@
int observed_quit;
} AVFContext;
-static void lock_frames(AVFContext* ctx)
-{
- pthread_mutex_lock(&ctx->frame_lock);
-}
-
-static void unlock_frames(AVFContext* ctx)
-{
- pthread_mutex_unlock(&ctx->frame_lock);
-}
-
/** FrameReciever class - delegate for AVCaptureSession
*/
@interface AVFFrameReceiver : NSObject
@@ -219,17 +213,8 @@ - (void) captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)videoFrame
fromConnection:(AVCaptureConnection *)connection
{
- lock_frames(_context);
-
- if (_context->current_frame != nil) {
- CFRelease(_context->current_frame);
- }
-
- _context->current_frame = (CMSampleBufferRef)CFRetain(videoFrame);
-
- unlock_frames(_context);
-
- ++_context->frames_captured;
+ CFRetain(videoFrame);
+ CMSimpleQueueEnqueue(_context->video_frames_queue, videoFrame);
}
@end
@@ -263,17 +248,8 @@ - (void) captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)audioFrame
fromConnection:(AVCaptureConnection *)connection
{
- lock_frames(_context);
-
- if (_context->current_audio_frame != nil) {
- CFRelease(_context->current_audio_frame);
- }
-
- _context->current_audio_frame = (CMSampleBufferRef)CFRetain(audioFrame);
-
- unlock_frames(_context);
-
- ++_context->audio_frames_captured;
+ CFRetain(audioFrame);
+ CMSimpleQueueEnqueue(_context->audio_frames_queue, audioFrame);
}
@end
@@ -288,6 +264,30 @@ static void destroy_context(AVFContext* ctx)
[ctx->avf_delegate release];
[ctx->avf_audio_delegate release];
+ CMSampleBufferRef frame;
+
+ if (ctx->video_frames_queue) {
+ frame = (CMSampleBufferRef)CMSimpleQueueDequeue(ctx->video_frames_queue);
+ while (frame) {
+ CFRelease(frame);
+ frame = (CMSampleBufferRef)CMSimpleQueueDequeue(ctx->video_frames_queue);
+ }
+
+ CFRelease(ctx->video_frames_queue);
+ ctx->video_frames_queue = NULL;
+ }
+
+ if (ctx->audio_frames_queue) {
+ frame = (CMSampleBufferRef)CMSimpleQueueDequeue(ctx->audio_frames_queue);
+ while (frame) {
+ CFRelease(frame);
+ frame = (CMSampleBufferRef)CMSimpleQueueDequeue(ctx->audio_frames_queue);
+ }
+
+ CFRelease(ctx->audio_frames_queue);
+ ctx->audio_frames_queue = NULL;
+ }
+
ctx->capture_session = NULL;
ctx->video_output = NULL;
ctx->audio_output = NULL;
@@ -298,12 +298,6 @@ static void destroy_context(AVFContext* ctx)
AudioConverterDispose(ctx->audio_converter);
ctx->audio_converter = NULL;
}
-
- pthread_mutex_destroy(&ctx->frame_lock);
-
- if (ctx->current_frame) {
- CFRelease(ctx->current_frame);
- }
}
static void parse_device_name(AVFormatContext *s)
@@ -631,18 +625,18 @@ static int get_video_config(AVFormatContext *s)
}
// Take stream info from the first frame.
- while (ctx->frames_captured < 1) {
+ while (CMSimpleQueueGetCount(ctx->video_frames_queue) < 1) {
CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0.1, YES);
}
- lock_frames(ctx);
+ CMSampleBufferRef frame = (CMSampleBufferRef)CMSimpleQueueDequeue(ctx->video_frames_queue);
ctx->video_stream_index = stream->index;
avpriv_set_pts_info(stream, 64, 1, avf_time_base);
- image_buffer = CMSampleBufferGetImageBuffer(ctx->current_frame);
- block_buffer = CMSampleBufferGetDataBuffer(ctx->current_frame);
+ image_buffer = CMSampleBufferGetImageBuffer(frame);
+ block_buffer = CMSampleBufferGetDataBuffer(frame);
if (image_buffer) {
image_buffer_size = CVImageBufferGetEncodedSize(image_buffer);
@@ -658,10 +652,7 @@ static int get_video_config(AVFormatContext *s)
stream->codecpar->format = ctx->pixel_format;
}
- CFRelease(ctx->current_frame);
- ctx->current_frame = nil;
-
- unlock_frames(ctx);
+ CFRelease(frame);
return 0;
}
@@ -681,27 +672,27 @@ static int get_audio_config(AVFormatContext *s)
}
// Take stream info from the first frame.
- while (ctx->audio_frames_captured < 1) {
+ while (CMSimpleQueueGetCount(ctx->audio_frames_queue) < 1) {
CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0.1, YES);
}
- lock_frames(ctx);
+ CMSampleBufferRef frame = (CMSampleBufferRef)CMSimpleQueueDequeue(ctx->audio_frames_queue);
ctx->audio_stream_index = stream->index;
avpriv_set_pts_info(stream, 64, 1, avf_time_base);
- format_desc = CMSampleBufferGetFormatDescription(ctx->current_audio_frame);
+ format_desc = CMSampleBufferGetFormatDescription(frame);
const AudioStreamBasicDescription *input_format = CMAudioFormatDescriptionGetStreamBasicDescription(format_desc);
if (!input_format) {
- unlock_frames(ctx);
+ CFRelease(frame);
av_log(s, AV_LOG_ERROR, "audio format not available\n");
return 1;
}
if (input_format->mFormatID != kAudioFormatLinearPCM) {
- unlock_frames(ctx);
+ CFRelease(frame);
av_log(s, AV_LOG_ERROR, "only PCM audio format are supported at the moment\n");
return 1;
}
@@ -781,16 +772,13 @@ static int get_audio_config(AVFormatContext *s)
if (must_convert) {
OSStatus ret = AudioConverterNew(input_format, &output_format, &ctx->audio_converter);
if (ret != noErr) {
- unlock_frames(ctx);
- av_log(s, AV_LOG_ERROR, "Error while allocating audio converter\n");
+ CFRelease(frame);
+ av_log_avfoundation_error("error while creating audio converter", ret);
return 1;
}
}
- CFRelease(ctx->current_audio_frame);
- ctx->current_audio_frame = nil;
-
- unlock_frames(ctx);
+ CFRelease(frame);
return 0;
}
@@ -808,8 +796,6 @@ static int avf_read_header(AVFormatContext *s)
ctx->num_video_devices = [devices count] + [devices_muxed count];
- pthread_mutex_init(&ctx->frame_lock, NULL);
-
#if !TARGET_OS_IPHONE && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1070
CGGetActiveDisplayList(0, NULL, &num_screens);
#endif
@@ -1010,6 +996,21 @@ static int avf_read_header(AVFormatContext *s)
// Initialize capture session
ctx->capture_session = [[AVCaptureSession alloc] init];
+ OSStatus ret;
+ ret = CMSimpleQueueCreate(kCFAllocatorDefault, MAX_QUEUED_FRAMES, &ctx->video_frames_queue);
+
+ if (ret != noErr) {
+ av_log_avfoundation_error("error while creating frame queue", ret);
+ goto fail;
+ }
+
+ ret = CMSimpleQueueCreate(kCFAllocatorDefault, MAX_QUEUED_FRAMES, &ctx->audio_frames_queue);
+
+ if (ret != noErr) {
+ av_log_avfoundation_error("error while creating frame queue", ret);
+ goto fail;
+ }
+
if (video_device && add_video_device(s, video_device)) {
goto fail;
}
@@ -1039,7 +1040,8 @@ static int avf_read_header(AVFormatContext *s)
fail:
[pool release];
destroy_context(ctx);
- return AVERROR(EIO);
+ av_log(s, AV_LOG_ERROR, "Error while opening AVfoundation capture session\n");
+ return AVERROR_EXTERNAL;
}
static int copy_cvpixelbuffer(AVFormatContext *s,
@@ -1088,38 +1090,35 @@ static int copy_cvpixelbuffer(AVFormatContext *s,
static int avf_read_packet(AVFormatContext *s, AVPacket *pkt)
{
OSStatus ret;
+ int status;
AVFContext* ctx = (AVFContext*)s->priv_data;
do {
- CVImageBufferRef image_buffer;
- CMBlockBufferRef block_buffer;
- lock_frames(ctx);
-
- if (ctx->current_frame != nil) {
- int status;
+ if (1 <= CMSimpleQueueGetCount(ctx->video_frames_queue)) {
int length = 0;
-
- image_buffer = CMSampleBufferGetImageBuffer(ctx->current_frame);
- block_buffer = CMSampleBufferGetDataBuffer(ctx->current_frame);
+ CMSampleBufferRef video_frame = (CMSampleBufferRef)CMSimpleQueueDequeue(ctx->video_frames_queue);
+ CVImageBufferRef image_buffer = CMSampleBufferGetImageBuffer(video_frame);;
+ CMBlockBufferRef block_buffer = CMSampleBufferGetDataBuffer(video_frame);
if (image_buffer != nil) {
length = (int)CVPixelBufferGetDataSize(image_buffer);
} else if (block_buffer != nil) {
length = (int)CMBlockBufferGetDataLength(block_buffer);
} else {
- unlock_frames(ctx);
+ CFRelease(video_frame);
return AVERROR(EINVAL);
}
- if (av_new_packet(pkt, length) < 0) {
- unlock_frames(ctx);
- return AVERROR(EIO);
+ status = av_new_packet(pkt, length);
+ if (status < 0) {
+ CFRelease(video_frame);
+ return status;
}
CMItemCount count;
CMSampleTimingInfo timing_info;
- if (CMSampleBufferGetOutputSampleTimingInfoArray(ctx->current_frame, 1, &timing_info, &count) == noErr) {
+ if (CMSampleBufferGetOutputSampleTimingInfoArray(video_frame, 1, &timing_info, &count) == noErr) {
AVRational timebase_q = av_make_q(1, timing_info.presentationTimeStamp.timescale);
pkt->pts = pkt->dts = av_rescale_q(timing_info.presentationTimeStamp.value, timebase_q, avf_time_base_q);
}
@@ -1133,18 +1132,18 @@ static int avf_read_packet(AVFormatContext *s, AVPacket *pkt)
status = 0;
ret = CMBlockBufferCopyDataBytes(block_buffer, 0, pkt->size, pkt->data);
if (ret != kCMBlockBufferNoErr) {
- status = AVERROR(EIO);
+ av_log_avfoundation_error("error while copying buffer data", ret);
+ status = AVERROR_EXTERNAL;
}
}
- CFRelease(ctx->current_frame);
- ctx->current_frame = nil;
+ CFRelease(video_frame);
if (status < 0) {
- unlock_frames(ctx);
return status;
}
- } else if (ctx->current_audio_frame != nil) {
- CMBlockBufferRef block_buffer = CMSampleBufferGetDataBuffer(ctx->current_audio_frame);
+ } else if (1 <= CMSimpleQueueGetCount(ctx->audio_frames_queue)) {
+ CMSampleBufferRef audio_frame = (CMSampleBufferRef)CMSimpleQueueDequeue(ctx->audio_frames_queue);
+ CMBlockBufferRef block_buffer = CMSampleBufferGetDataBuffer(audio_frame);
size_t input_size = CMBlockBufferGetDataLength(block_buffer);
int buffer_size = input_size / ctx->audio_buffers;
@@ -1170,8 +1169,9 @@ static int avf_read_packet(AVFormatContext *s, AVPacket *pkt)
if (ret != kCMBlockBufferNoErr) {
av_free(input_buffer);
- unlock_frames(ctx);
- return AVERROR(EIO);
+ CFRelease(audio_frame);
+ av_log_avfoundation_error("error while accessing audio buffer data", ret);
+ return AVERROR_EXTERNAL;
}
}
@@ -1188,23 +1188,25 @@ static int avf_read_packet(AVFormatContext *s, AVPacket *pkt)
av_free(input_buffer);
if (ret != noErr) {
- unlock_frames(ctx);
- return AVERROR(EIO);
+ CFRelease(audio_frame);
+ av_log_avfoundation_error("error while converting audio data", ret);
+ return AVERROR_EXTERNAL;
}
pkt->size = output_buffer.mBuffers[0].mDataByteSize;
} else {
ret = CMBlockBufferCopyDataBytes(block_buffer, 0, pkt->size, pkt->data);
if (ret != kCMBlockBufferNoErr) {
- unlock_frames(ctx);
- return AVERROR(EIO);
+ CFRelease(audio_frame);
+ av_log_avfoundation_error("error while copying audio data", ret);
+ return AVERROR_EXTERNAL;
}
}
CMItemCount count;
CMSampleTimingInfo timing_info;
- if (CMSampleBufferGetOutputSampleTimingInfoArray(ctx->current_audio_frame, 1, &timing_info, &count) == noErr) {
+ if (CMSampleBufferGetOutputSampleTimingInfoArray(audio_frame, 1, &timing_info, &count) == noErr) {
AVRational timebase_q = av_make_q(1, timing_info.presentationTimeStamp.timescale);
pkt->pts = pkt->dts = av_rescale_q(timing_info.presentationTimeStamp.value, timebase_q, avf_time_base_q);
}
@@ -1212,21 +1214,15 @@ static int avf_read_packet(AVFormatContext *s, AVPacket *pkt)
pkt->stream_index = ctx->audio_stream_index;
pkt->flags |= AV_PKT_FLAG_KEY;
- CFRelease(ctx->current_audio_frame);
- ctx->current_audio_frame = nil;
-
- unlock_frames(ctx);
+ CFRelease(audio_frame);
} else {
pkt->data = NULL;
- unlock_frames(ctx);
if (ctx->observed_quit) {
return AVERROR_EOF;
} else {
return AVERROR(EAGAIN);
}
}
-
- unlock_frames(ctx);
} while (!pkt->data);
return 0;
* Use a CMSimpleQueueEnqueue with maximum length to queue and process incoming audio and video frames. * Log avfoundation errors. * Use AVERROR_EXTERNAL instead of AVERROR(EIO) in avfoundation errors. Signed-off-by: Romain Beauxis <toots@rastageeks.org> — This is the second patch of a series of 3 that fix, cleanup and enhance the avfoundation implementation for libavdevice. These patches come from an actual user-facing application relying on libavdevice’s implementation of avfoundation audio input. Without them, Avfoundation is practically unusable as it will: * Refuse to process certain specific audio input format that are actually returned by the OS for some users (packed PCM audio) * Drop audio frames, resulting in corrupted audio input. This might have been unnoticed with video frames but this makes avfoundation essentially unusable for audio. The patches are now being included in our production build so they are tested and usable in production. This patch fixes the concurrency model. Avfoundation runs its own producing thread to send produced frames and ffmpeg runs its own thread to consume them. The existing implementation stores the last transmitted frame and uses a mutex to avoid concurrent access. However, this leads to situations where upcoming frames can be dropped if the ffmpeg thread is acessing the latest frame. This happens even when the thread would otherwise catch up and process frames fast enought. This patches changes this implementation to use a buffer queue with a max queue length and encapsulated thread-safety. This greatly simplifies the logic of the calling code and gives the consuming thread a chance to process all frames concurrently to the producing thread while avoiding memory leaks. Changes: v2: None v3: Switched queue implementation to CMSimpleQueue v4: None v5: Fix indentation/wrapping v6: Fix audio/video frame queue cleanup logic v7: Enhance avfoundation error reporting: add human-readable description, use AVERROR_EXTERNAL instead of AVERROR(EIO) libavdevice/avfoundation.m | 196 ++++++++++++++++++------------------- 1 file changed, 96 insertions(+), 100 deletions(-)