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1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 // Note: ported from Chromium commit head: 09ea0d2
5 // Note: it's also merged with generic_v4l2_device.cc (head: a9d98e6)
6 
7 #include <errno.h>
8 #include <fcntl.h>
9 #include <poll.h>
10 #include <string.h>
11 #include <sys/eventfd.h>
12 #include <sys/ioctl.h>
13 #include <sys/mman.h>
14 
15 #include "base/numerics/safe_conversions.h"
16 #include "base/posix/eintr_wrapper.h"
17 #include "base/strings/stringprintf.h"
18 #include "v4l2_device.h"
19 
20 #define DVLOGF(level) DVLOG(level) << __func__ << "(): "
21 #define VLOGF(level) VLOG(level) << __func__ << "(): "
22 #define VPLOGF(level) VPLOG(level) << __func__ << "(): "
23 
24 namespace media {
25 
V4L2Device()26 V4L2Device::V4L2Device() {}
27 
~V4L2Device()28 V4L2Device::~V4L2Device() {
29   CloseDevice();
30 }
31 
32 // static
V4L2PixFmtToVideoPixelFormat(uint32_t pix_fmt)33 VideoPixelFormat V4L2Device::V4L2PixFmtToVideoPixelFormat(uint32_t pix_fmt) {
34   switch (pix_fmt) {
35     case V4L2_PIX_FMT_NV12:
36     case V4L2_PIX_FMT_NV12M:
37       return PIXEL_FORMAT_NV12;
38 
39     case V4L2_PIX_FMT_MT21:
40       return PIXEL_FORMAT_MT21;
41 
42     case V4L2_PIX_FMT_YUV420:
43     case V4L2_PIX_FMT_YUV420M:
44       return PIXEL_FORMAT_I420;
45 
46     case V4L2_PIX_FMT_YVU420:
47       return PIXEL_FORMAT_YV12;
48 
49     case V4L2_PIX_FMT_YUV422M:
50       return PIXEL_FORMAT_I422;
51 
52     case V4L2_PIX_FMT_RGB32:
53       return PIXEL_FORMAT_ARGB;
54 
55     default:
56       DVLOGF(1) << "Add more cases as needed";
57       return PIXEL_FORMAT_UNKNOWN;
58   }
59 }
60 
61 // static
VideoPixelFormatToV4L2PixFmt(VideoPixelFormat format)62 uint32_t V4L2Device::VideoPixelFormatToV4L2PixFmt(VideoPixelFormat format) {
63   switch (format) {
64     case PIXEL_FORMAT_NV12:
65       return V4L2_PIX_FMT_NV12M;
66 
67     case PIXEL_FORMAT_MT21:
68       return V4L2_PIX_FMT_MT21;
69 
70     case PIXEL_FORMAT_I420:
71       return V4L2_PIX_FMT_YUV420M;
72 
73     case PIXEL_FORMAT_YV12:
74       return V4L2_PIX_FMT_YVU420;
75 
76     default:
77       LOG(FATAL) << "Add more cases as needed";
78       return 0;
79   }
80 }
81 
82 // static
VideoCodecProfileToV4L2PixFmt(VideoCodecProfile profile)83 uint32_t V4L2Device::VideoCodecProfileToV4L2PixFmt(VideoCodecProfile profile) {
84   if (profile >= H264PROFILE_MIN && profile <= H264PROFILE_MAX) {
85       return V4L2_PIX_FMT_H264;
86   } else if (profile >= VP8PROFILE_MIN && profile <= VP8PROFILE_MAX) {
87       return V4L2_PIX_FMT_VP8;
88   } else if (profile >= VP9PROFILE_MIN && profile <= VP9PROFILE_MAX) {
89       return V4L2_PIX_FMT_VP9;
90   } else {
91     LOG(FATAL) << "Add more cases as needed";
92     return 0;
93   }
94 }
95 
96 // static
V4L2PixFmtToVideoCodecProfiles(uint32_t pix_fmt,bool is_encoder)97 std::vector<VideoCodecProfile> V4L2Device::V4L2PixFmtToVideoCodecProfiles(
98     uint32_t pix_fmt,
99     bool is_encoder) {
100   VideoCodecProfile min_profile, max_profile;
101   std::vector<VideoCodecProfile> profiles;
102 
103   switch (pix_fmt) {
104     case V4L2_PIX_FMT_H264:
105       if (is_encoder) {
106         // TODO(posciak): need to query the device for supported H.264 profiles,
107         // for now choose Main as a sensible default.
108         min_profile = H264PROFILE_MAIN;
109         max_profile = H264PROFILE_MAIN;
110       } else {
111         min_profile = H264PROFILE_MIN;
112         max_profile = H264PROFILE_MAX;
113       }
114       break;
115 
116     case V4L2_PIX_FMT_VP8:
117       min_profile = VP8PROFILE_MIN;
118       max_profile = VP8PROFILE_MAX;
119       break;
120 
121     case V4L2_PIX_FMT_VP9:
122       min_profile = VP9PROFILE_MIN;
123       max_profile = VP9PROFILE_MAX;
124       break;
125 
126     default:
127       VLOGF(1) << "Unhandled pixelformat " << std::hex << "0x" << pix_fmt;
128       return profiles;
129   }
130 
131   for (int profile = min_profile; profile <= max_profile; ++profile)
132     profiles.push_back(static_cast<VideoCodecProfile>(profile));
133 
134   return profiles;
135 }
136 
Ioctl(int request,void * arg)137 int V4L2Device::Ioctl(int request, void* arg) {
138   DCHECK(device_fd_.is_valid());
139   return HANDLE_EINTR(ioctl(device_fd_.get(), request, arg));
140 }
141 
Poll(bool poll_device,bool * event_pending)142 bool V4L2Device::Poll(bool poll_device, bool* event_pending) {
143   struct pollfd pollfds[2];
144   nfds_t nfds;
145   int pollfd = -1;
146 
147   pollfds[0].fd = device_poll_interrupt_fd_.get();
148   pollfds[0].events = POLLIN | POLLERR;
149   nfds = 1;
150 
151   if (poll_device) {
152     DVLOGF(5) << "Poll(): adding device fd to poll() set";
153     pollfds[nfds].fd = device_fd_.get();
154     pollfds[nfds].events = POLLIN | POLLOUT | POLLERR | POLLPRI;
155     pollfd = nfds;
156     nfds++;
157   }
158 
159   if (HANDLE_EINTR(poll(pollfds, nfds, -1)) == -1) {
160     VPLOGF(1) << "poll() failed";
161     return false;
162   }
163   *event_pending = (pollfd != -1 && pollfds[pollfd].revents & POLLPRI);
164   return true;
165 }
166 
Mmap(void * addr,unsigned int len,int prot,int flags,unsigned int offset)167 void* V4L2Device::Mmap(void* addr,
168                        unsigned int len,
169                        int prot,
170                        int flags,
171                        unsigned int offset) {
172   DCHECK(device_fd_.is_valid());
173   return mmap(addr, len, prot, flags, device_fd_.get(), offset);
174 }
175 
Munmap(void * addr,unsigned int len)176 void V4L2Device::Munmap(void* addr, unsigned int len) {
177   munmap(addr, len);
178 }
179 
SetDevicePollInterrupt()180 bool V4L2Device::SetDevicePollInterrupt() {
181   DVLOGF(4);
182 
183   const uint64_t buf = 1;
184   if (HANDLE_EINTR(write(device_poll_interrupt_fd_.get(), &buf, sizeof(buf))) ==
185       -1) {
186     VPLOGF(1) << "write() failed";
187     return false;
188   }
189   return true;
190 }
191 
ClearDevicePollInterrupt()192 bool V4L2Device::ClearDevicePollInterrupt() {
193   DVLOGF(5);
194 
195   uint64_t buf;
196   if (HANDLE_EINTR(read(device_poll_interrupt_fd_.get(), &buf, sizeof(buf))) ==
197       -1) {
198     if (errno == EAGAIN) {
199       // No interrupt flag set, and we're reading nonblocking.  Not an error.
200       return true;
201     } else {
202       VPLOGF(1) << "read() failed";
203       return false;
204     }
205   }
206   return true;
207 }
208 
Open(Type type,uint32_t v4l2_pixfmt)209 bool V4L2Device::Open(Type type, uint32_t v4l2_pixfmt) {
210   VLOGF(2);
211   std::string path = GetDevicePathFor(type, v4l2_pixfmt);
212 
213   if (path.empty()) {
214     VLOGF(1) << "No devices supporting " << std::hex << "0x" << v4l2_pixfmt
215              << " for type: " << static_cast<int>(type);
216     return false;
217   }
218 
219   if (!OpenDevicePath(path, type)) {
220     VLOGF(1) << "Failed opening " << path;
221     return false;
222   }
223 
224   device_poll_interrupt_fd_.reset(eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC));
225   if (!device_poll_interrupt_fd_.is_valid()) {
226     VLOGF(1) << "Failed creating a poll interrupt fd";
227     return false;
228   }
229 
230   return true;
231 }
232 
GetDmabufsForV4L2Buffer(int index,size_t num_planes,enum v4l2_buf_type buf_type)233 std::vector<base::ScopedFD> V4L2Device::GetDmabufsForV4L2Buffer(
234     int index,
235     size_t num_planes,
236     enum v4l2_buf_type buf_type) {
237   VLOGF(2);
238   DCHECK(V4L2_TYPE_IS_MULTIPLANAR(buf_type));
239 
240   std::vector<base::ScopedFD> dmabuf_fds;
241   for (size_t i = 0; i < num_planes; ++i) {
242     struct v4l2_exportbuffer expbuf;
243     memset(&expbuf, 0, sizeof(expbuf));
244     expbuf.type = buf_type;
245     expbuf.index = index;
246     expbuf.plane = i;
247     expbuf.flags = O_CLOEXEC;
248     if (Ioctl(VIDIOC_EXPBUF, &expbuf) != 0) {
249       dmabuf_fds.clear();
250       break;
251     }
252 
253     dmabuf_fds.push_back(base::ScopedFD(expbuf.fd));
254   }
255 
256   return dmabuf_fds;
257 }
258 
259 VideoDecodeAccelerator::SupportedProfiles
GetSupportedDecodeProfiles(const size_t num_formats,const uint32_t pixelformats[])260 V4L2Device::GetSupportedDecodeProfiles(const size_t num_formats,
261                                        const uint32_t pixelformats[]) {
262   VideoDecodeAccelerator::SupportedProfiles supported_profiles;
263 
264   Type type = Type::kDecoder;
265   const auto& devices = GetDevicesForType(type);
266   for (const auto& device : devices) {
267     if (!OpenDevicePath(device.first, type)) {
268       VLOGF(1) << "Failed opening " << device.first;
269       continue;
270     }
271 
272     const auto& profiles =
273         EnumerateSupportedDecodeProfiles(num_formats, pixelformats);
274     supported_profiles.insert(supported_profiles.end(), profiles.begin(),
275                               profiles.end());
276     CloseDevice();
277   }
278 
279   return supported_profiles;
280 }
281 
GetSupportedResolution(uint32_t pixelformat,Size * min_resolution,Size * max_resolution)282 void V4L2Device::GetSupportedResolution(uint32_t pixelformat,
283                                         Size* min_resolution,
284                                         Size* max_resolution) {
285   max_resolution->SetSize(0, 0);
286   min_resolution->SetSize(0, 0);
287   v4l2_frmsizeenum frame_size;
288   memset(&frame_size, 0, sizeof(frame_size));
289   frame_size.pixel_format = pixelformat;
290   for (; Ioctl(VIDIOC_ENUM_FRAMESIZES, &frame_size) == 0; ++frame_size.index) {
291     if (frame_size.type == V4L2_FRMSIZE_TYPE_DISCRETE) {
292       if (frame_size.discrete.width >=
293               base::checked_cast<uint32_t>(max_resolution->width()) &&
294           frame_size.discrete.height >=
295               base::checked_cast<uint32_t>(max_resolution->height())) {
296         max_resolution->SetSize(frame_size.discrete.width,
297                                 frame_size.discrete.height);
298       }
299       if (min_resolution->IsEmpty() ||
300           (frame_size.discrete.width <=
301                base::checked_cast<uint32_t>(min_resolution->width()) &&
302            frame_size.discrete.height <=
303                base::checked_cast<uint32_t>(min_resolution->height()))) {
304         min_resolution->SetSize(frame_size.discrete.width,
305                                 frame_size.discrete.height);
306       }
307     } else if (frame_size.type == V4L2_FRMSIZE_TYPE_STEPWISE ||
308                frame_size.type == V4L2_FRMSIZE_TYPE_CONTINUOUS) {
309       max_resolution->SetSize(frame_size.stepwise.max_width,
310                               frame_size.stepwise.max_height);
311       min_resolution->SetSize(frame_size.stepwise.min_width,
312                               frame_size.stepwise.min_height);
313       break;
314     }
315   }
316   if (max_resolution->IsEmpty()) {
317     max_resolution->SetSize(1920, 1088);
318     VLOGF(1) << "GetSupportedResolution failed to get maximum resolution for "
319              << "fourcc " << std::hex << pixelformat
320              << ", fall back to " << max_resolution->ToString();
321   }
322   if (min_resolution->IsEmpty()) {
323     min_resolution->SetSize(16, 16);
324     VLOGF(1) << "GetSupportedResolution failed to get minimum resolution for "
325              << "fourcc " << std::hex << pixelformat
326              << ", fall back to " << min_resolution->ToString();
327   }
328 }
329 
EnumerateSupportedPixelformats(v4l2_buf_type buf_type)330 std::vector<uint32_t> V4L2Device::EnumerateSupportedPixelformats(
331     v4l2_buf_type buf_type) {
332   std::vector<uint32_t> pixelformats;
333 
334   v4l2_fmtdesc fmtdesc;
335   memset(&fmtdesc, 0, sizeof(fmtdesc));
336   fmtdesc.type = buf_type;
337 
338   for (; Ioctl(VIDIOC_ENUM_FMT, &fmtdesc) == 0; ++fmtdesc.index) {
339     DVLOGF(3) << "Found " << fmtdesc.description << std::hex << " (0x"
340               << fmtdesc.pixelformat << ")";
341     pixelformats.push_back(fmtdesc.pixelformat);
342   }
343 
344   return pixelformats;
345 }
346 
347 VideoDecodeAccelerator::SupportedProfiles
EnumerateSupportedDecodeProfiles(const size_t num_formats,const uint32_t pixelformats[])348 V4L2Device::EnumerateSupportedDecodeProfiles(const size_t num_formats,
349                                              const uint32_t pixelformats[]) {
350   VideoDecodeAccelerator::SupportedProfiles profiles;
351 
352   const auto& supported_pixelformats =
353       EnumerateSupportedPixelformats(V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE);
354 
355   for (uint32_t pixelformat : supported_pixelformats) {
356     if (std::find(pixelformats, pixelformats + num_formats, pixelformat) ==
357         pixelformats + num_formats)
358       continue;
359 
360     VideoDecodeAccelerator::SupportedProfile profile;
361     GetSupportedResolution(pixelformat, &profile.min_resolution,
362                            &profile.max_resolution);
363 
364     const auto video_codec_profiles =
365         V4L2PixFmtToVideoCodecProfiles(pixelformat, false);
366 
367     for (const auto& video_codec_profile : video_codec_profiles) {
368       profile.profile = video_codec_profile;
369       profiles.push_back(profile);
370 
371       DVLOGF(3) << "Found decoder profile " << GetProfileName(profile.profile)
372                 << ", resolutions: " << profile.min_resolution.ToString() << " "
373                 << profile.max_resolution.ToString();
374     }
375   }
376 
377   return profiles;
378 }
379 
OpenDevicePath(const std::string & path,Type type)380 bool V4L2Device::OpenDevicePath(const std::string& path, Type type) {
381   DCHECK(!device_fd_.is_valid());
382 
383   device_fd_.reset(
384       HANDLE_EINTR(open(path.c_str(), O_RDWR | O_NONBLOCK | O_CLOEXEC)));
385   if (!device_fd_.is_valid())
386     return false;
387 
388   return true;
389 }
390 
CloseDevice()391 void V4L2Device::CloseDevice() {
392   VLOGF(2);
393   device_fd_.reset();
394 }
395 
EnumerateDevicesForType(Type type)396 void V4L2Device::EnumerateDevicesForType(Type type) {
397   static const std::string kDecoderDevicePattern = "/dev/video-dec";
398   std::string device_pattern;
399   v4l2_buf_type buf_type;
400   switch (type) {
401     case Type::kDecoder:
402       device_pattern = kDecoderDevicePattern;
403       buf_type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
404       break;
405     default:
406       LOG(ERROR) << "Only decoder type is supported!!";
407       return;
408   }
409 
410   std::vector<std::string> candidate_paths;
411 
412   // TODO(posciak): Remove this legacy unnumbered device once
413   // all platforms are updated to use numbered devices.
414   candidate_paths.push_back(device_pattern);
415 
416   // We are sandboxed, so we can't query directory contents to check which
417   // devices are actually available. Try to open the first 10; if not present,
418   // we will just fail to open immediately.
419   for (int i = 0; i < 10; ++i) {
420     candidate_paths.push_back(
421         base::StringPrintf("%s%d", device_pattern.c_str(), i));
422   }
423 
424   Devices devices;
425   for (const auto& path : candidate_paths) {
426     if (!OpenDevicePath(path, type))
427       continue;
428 
429     const auto& supported_pixelformats =
430         EnumerateSupportedPixelformats(buf_type);
431     if (!supported_pixelformats.empty()) {
432       DVLOGF(3) << "Found device: " << path;
433       devices.push_back(std::make_pair(path, supported_pixelformats));
434     }
435 
436     CloseDevice();
437   }
438 
439   DCHECK_EQ(devices_by_type_.count(type), 0u);
440   devices_by_type_[type] = devices;
441 }
442 
GetDevicesForType(Type type)443 const V4L2Device::Devices& V4L2Device::GetDevicesForType(Type type) {
444   if (devices_by_type_.count(type) == 0)
445     EnumerateDevicesForType(type);
446 
447   DCHECK_NE(devices_by_type_.count(type), 0u);
448   return devices_by_type_[type];
449 }
450 
GetDevicePathFor(Type type,uint32_t pixfmt)451 std::string V4L2Device::GetDevicePathFor(Type type, uint32_t pixfmt) {
452   const Devices& devices = GetDevicesForType(type);
453 
454   for (const auto& device : devices) {
455     if (std::find(device.second.begin(), device.second.end(), pixfmt) !=
456         device.second.end())
457       return device.first;
458   }
459 
460   return std::string();
461 }
462 
463 }  //  namespace media
464