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Use the preferred capture format on windows.

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The existing windows dshow capture code was ignoring the requested
capture format when enumerating preferred formats. This CL changes
the behavior to move the requested format to the start of the
preferred list. This should fix an issue causing MJPEG to be not
selected on certain devices because other formats were preferred,
resulting in reduced framerates for HD capture (USB 2.0 throughput
isn't high enough to support capturing 30fps 720p I420 data, and many
cameras, even internal, are on the USB 2.0 bus).

Note that Chromium has yet a different implementation, which is if
MJPEG is selected, it claims to *only* support MJPEG and no other
formats. This solution seems more correct; if, for some reason,
MJPEG was listed as supported but isn't asked of the pin, this
code will still produce some output, just possibly at a lower framerate
or resolution.

Bug: None
Change-Id: Id86f345936f6f32e08beec02925e41056c87a544
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/130843
Commit-Queue: Tommi <tommi@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27412}
This commit is contained in:
Noah Richards 2019-04-01 16:53:33 -07:00 committed by Commit Bot
parent 2cc368fd7a
commit a64f397397
1 changed files with 64 additions and 40 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

104
modules/video_capture/windows/sink_filter_ds.cc
View File

@ -236,7 +236,27 @@ bool TranslateMediaTypeToVideoCaptureCapability(
class MediaTypesEnum : public IEnumMediaTypes {
public:
MediaTypesEnum(const VideoCaptureCapability& capability)
: capability_(capability) {}
: capability_(capability),
format_preference_order_(
{// Default preferences, sorted by cost-to-convert-to-i420.
VideoType::kI420, VideoType::kYUY2, VideoType::kRGB24,
VideoType::kUYVY, VideoType::kMJPEG}) {
// Use the preferred video type, if supported.
auto it = std::find(format_preference_order_.begin(),
format_preference_order_.end(), capability_.videoType);
if (it != format_preference_order_.end()) {
RTC_LOG(LS_INFO) << "Selected video type: " << *it;
// Move it to the front of the list, if it isn't already there.
if (it != format_preference_order_.begin()) {
format_preference_order_.splice(format_preference_order_.begin(),
format_preference_order_, it,
std::next(it));
}
} else {
RTC_LOG(LS_WARNING) << "Unsupported video type: " << *it
<< ", using default preference list.";
}
}
protected:
virtual ~MediaTypesEnum() {}
@ -264,10 +284,9 @@ class MediaTypesEnum : public IEnumMediaTypes {
if (fetched)
*fetched = 0;
// Note, must match switch statement below.
constexpr int kNumTypes = 5;
for (ULONG i = 0; i < count && pos_ < kNumTypes; ++i) {
for (ULONG i = 0;
i < count && pos_ < static_cast<int>(format_preference_order_.size());
++i) {
AM_MEDIA_TYPE* media_type = reinterpret_cast<AM_MEDIA_TYPE*>(
CoTaskMemAlloc(sizeof(AM_MEDIA_TYPE)));
ZeroMemory(media_type, sizeof(*media_type));
@ -289,39 +308,9 @@ class MediaTypesEnum : public IEnumMediaTypes {
media_type->formattype = FORMAT_VideoInfo;
media_type->bTemporalCompression = FALSE;
switch (pos_++) {
case 0:
// Note: The previous implementation had a bug that caused this
// format to always be omitted. Perhaps including it now will have
// a sideffect.
vih->bmiHeader.biCompression = MAKEFOURCC('I', '4', '2', '0');
vih->bmiHeader.biBitCount = 12; // bit per pixel
media_type->subtype = MEDIASUBTYPE_I420;
break;
case 1:
vih->bmiHeader.biCompression = MAKEFOURCC('Y', 'U', 'Y', '2');
vih->bmiHeader.biBitCount = 16; // bit per pixel
media_type->subtype = MEDIASUBTYPE_YUY2;
break;
case 2:
vih->bmiHeader.biCompression = BI_RGB;
vih->bmiHeader.biBitCount = 24; // bit per pixel
media_type->subtype = MEDIASUBTYPE_RGB24;
break;
case 3:
vih->bmiHeader.biCompression = MAKEFOURCC('U', 'Y', 'V', 'Y');
vih->bmiHeader.biBitCount = 16; // bit per pixel
media_type->subtype = MEDIASUBTYPE_UYVY;
break;
case 4:
vih->bmiHeader.biCompression = MAKEFOURCC('M', 'J', 'P', 'G');
vih->bmiHeader.biBitCount = 12; // bit per pixel
media_type->subtype = MEDIASUBTYPE_MJPG;
break;
default:
RTC_NOTREACHED();
break;
}
// Set format information.
auto format_it = std::next(format_preference_order_.begin(), pos_++);
SetMediaInfoFromVideoType(*format_it, &vih->bmiHeader, media_type);
vih->bmiHeader.biWidth = capability_.width;
vih->bmiHeader.biHeight = capability_.height;
@ -335,8 +324,42 @@ class MediaTypesEnum : public IEnumMediaTypes {
if (fetched)
++(*fetched);
}
RTC_DCHECK(pos_ <= kNumTypes);
return pos_ == kNumTypes ? S_FALSE : S_OK;
return pos_ == static_cast<int>(format_preference_order_.size()) ? S_FALSE
: S_OK;
}
static void SetMediaInfoFromVideoType(VideoType video_type,
BITMAPINFOHEADER* bitmap_header,
AM_MEDIA_TYPE* media_type) {
switch (video_type) {
case VideoType::kI420:
bitmap_header->biCompression = MAKEFOURCC('I', '4', '2', '0');
bitmap_header->biBitCount = 12; // bit per pixel
media_type->subtype = MEDIASUBTYPE_I420;
break;
case VideoType::kYUY2:
bitmap_header->biCompression = MAKEFOURCC('Y', 'U', 'Y', '2');
bitmap_header->biBitCount = 16; // bit per pixel
media_type->subtype = MEDIASUBTYPE_YUY2;
break;
case VideoType::kRGB24:
bitmap_header->biCompression = BI_RGB;
bitmap_header->biBitCount = 24; // bit per pixel
media_type->subtype = MEDIASUBTYPE_RGB24;
break;
case VideoType::kUYVY:
bitmap_header->biCompression = MAKEFOURCC('U', 'Y', 'V', 'Y');
bitmap_header->biBitCount = 16; // bit per pixel
media_type->subtype = MEDIASUBTYPE_UYVY;
break;
case VideoType::kMJPEG:
bitmap_header->biCompression = MAKEFOURCC('M', 'J', 'P', 'G');
bitmap_header->biBitCount = 12; // bit per pixel
media_type->subtype = MEDIASUBTYPE_MJPG;
break;
default:
RTC_NOTREACHED();
}
}
STDMETHOD(Skip)(ULONG count) {
@ -351,6 +374,7 @@ class MediaTypesEnum : public IEnumMediaTypes {
int pos_ = 0;
const VideoCaptureCapability capability_;
std::list<VideoType> format_preference_order_;
};
} // namespace