Refactor from global variables into class members.

The first step on the way of supporting multiple devices.

diff --git a/bmusb.cpp b/bmusb.cpp
index e7d9fbe55c2148d76b3a6e921522da62c3d4341a..8d0918c2215bd6b750ba015b421d50b4c3f38c72 100644 (file)
--- a/bmusb.cpp
+++ b/bmusb.cpp
@@ -29,11 +29,7 @@
 #include "bmusb.h"
 
 using namespace std;
-
-static int current_register = 0;
-
-#define NUM_REGISTERS 60
-uint8_t register_file[NUM_REGISTERS];
+using namespace std::placeholders;
 
 #define WIDTH 1280
 #define HEIGHT 750  /* 30 lines ancillary data? */
@@ -49,23 +45,6 @@ uint8_t register_file[NUM_REGISTERS];
 
 FILE *audiofp;
 
-FrameAllocator::Frame current_video_frame;
-FrameAllocator::Frame current_audio_frame;
-
-struct QueuedFrame {
-       uint16_t timecode;
-       uint16_t format;
-       FrameAllocator::Frame frame;
-};
-
-mutex queue_lock;
-condition_variable queues_not_empty;
-deque<QueuedFrame> pending_video_frames;
-deque<QueuedFrame> pending_audio_frames;
-
-thread usb_thread;
-atomic<bool> should_quit;
-
 FrameAllocator::~FrameAllocator() {}
 
 #define NUM_QUEUED_FRAMES 8
@@ -113,10 +92,6 @@ void MallocFrameAllocator::release_frame(Frame frame)
        freelist.push(unique_ptr<uint8_t[]>(frame.data));
 }
 
-FrameAllocator *video_frame_allocator = nullptr;
-FrameAllocator *audio_frame_allocator = nullptr;
-frame_callback_t frame_callback = nullptr;
-
 bool uint16_less_than_with_wraparound(uint16_t a, uint16_t b)
 {
        if (a == b) {
@@ -129,7 +104,7 @@ bool uint16_less_than_with_wraparound(uint16_t a, uint16_t b)
        }
 }
 
-void queue_frame(uint16_t format, uint16_t timecode, FrameAllocator::Frame frame, deque<QueuedFrame> *q)
+void BMUSBCapture::queue_frame(uint16_t format, uint16_t timecode, FrameAllocator::Frame frame, deque<QueuedFrame> *q)
 {
        if (!q->empty() && !uint16_less_than_with_wraparound(q->back().timecode, timecode)) {
                printf("Blocks going backwards: prev=0x%04x, cur=0x%04x (dropped)\n",
@@ -164,11 +139,11 @@ void dump_audio_block(uint8_t *audio_start, size_t audio_len)
        fwrite(audio_start + AUDIO_HEADER_SIZE, 1, audio_len - AUDIO_HEADER_SIZE, audiofp);
 }
 
-void dequeue_thread()
+void BMUSBCapture::dequeue_thread()
 {
        for ( ;; ) {
                unique_lock<mutex> lock(queue_lock);
-               queues_not_empty.wait(lock, []{ return !pending_video_frames.empty() && !pending_audio_frames.empty(); });
+               queues_not_empty.wait(lock, [this]{ return !pending_video_frames.empty() && !pending_audio_frames.empty(); });
 
                uint16_t video_timecode = pending_video_frames.front().timecode;
                uint16_t audio_timecode = pending_audio_frames.front().timecode;
@@ -203,7 +178,7 @@ void dequeue_thread()
        }
 }
 
-void start_new_frame(const uint8_t *start)
+void BMUSBCapture::start_new_frame(const uint8_t *start)
 {
        uint16_t format = (start[3] << 8) | start[2];
        uint16_t timecode = (start[1] << 8) | start[0];
@@ -225,7 +200,7 @@ void start_new_frame(const uint8_t *start)
        //}
 }
 
-void start_new_audio_block(const uint8_t *start)
+void BMUSBCapture::start_new_audio_block(const uint8_t *start)
 {
        uint16_t format = (start[3] << 8) | start[2];
        uint16_t timecode = (start[1] << 8) | start[0];
@@ -511,7 +486,7 @@ void decode_packs(const libusb_transfer *xfr,
        }
 }
 
-static void cb_xfr(struct libusb_transfer *xfr)
+void BMUSBCapture::cb_xfr(struct libusb_transfer *xfr)
 {
        if (xfr->status != LIBUSB_TRANSFER_COMPLETED) {
                fprintf(stderr, "transfer status %d\n", xfr->status);
@@ -519,11 +494,14 @@ static void cb_xfr(struct libusb_transfer *xfr)
                exit(3);
        }
 
+       assert(xfr->user_data != nullptr);
+       BMUSBCapture *usb = static_cast<BMUSBCapture *>(xfr->user_data);
+
        if (xfr->type == LIBUSB_TRANSFER_TYPE_ISOCHRONOUS) {
                if (xfr->endpoint == 0x84) {
-                       decode_packs(xfr, "DeckLinkAudioResyncT", 20, &current_audio_frame, "audio", start_new_audio_block);
+                       decode_packs(xfr, "DeckLinkAudioResyncT", 20, &usb->current_audio_frame, "audio", bind(&BMUSBCapture::start_new_audio_block, usb, _1));
                } else {
-                       decode_packs(xfr, "\x00\x00\xff\xff", 4, &current_video_frame, "video", start_new_frame);
+                       decode_packs(xfr, "\x00\x00\xff\xff", 4, &usb->current_video_frame, "video", bind(&BMUSBCapture::start_new_frame, usb, _1));
                }
        }
        if (xfr->type == LIBUSB_TRANSFER_TYPE_CONTROL) {
@@ -537,19 +515,19 @@ static void cb_xfr(struct libusb_transfer *xfr)
                                setup->wIndex, buf[0], buf[1], buf[2], buf[3]);
                }
 #else
-               memcpy(register_file + current_register, buf, 4);
-               current_register = (current_register + 4) % NUM_REGISTERS;
-               if (current_register == 0) {
+               memcpy(usb->register_file + usb->current_register, buf, 4);
+               usb->current_register = (usb->current_register + 4) % NUM_BMUSB_REGISTERS;
+               if (usb->current_register == 0) {
                        // read through all of them
                        printf("register dump:");
-                       for (int i = 0; i < NUM_REGISTERS; i += 4) {
-                               printf(" 0x%02x%02x%02x%02x", register_file[i], register_file[i + 1], register_file[i + 2], register_file[i + 3]);
+                       for (int i = 0; i < NUM_BMUSB_REGISTERS; i += 4) {
+                               printf(" 0x%02x%02x%02x%02x", usb->register_file[i], usb->register_file[i + 1], usb->register_file[i + 2], usb->register_file[i + 3]);
                        }
                        printf("\n");
                }
                libusb_fill_control_setup(xfr->buffer,
                    LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN, /*request=*/214, /*value=*/0,
-                       /*index=*/current_register, /*length=*/4);
+                       /*index=*/usb->current_register, /*length=*/4);
 #endif
        }
 
@@ -572,7 +550,7 @@ static void cb_xfr(struct libusb_transfer *xfr)
        }
 }
 
-void usb_thread_func()
+void BMUSBCapture::usb_thread_func()
 {
        printf("usb thread started\n");
 
@@ -589,32 +567,7 @@ void usb_thread_func()
        }
 }
 
-FrameAllocator *get_video_frame_allocator()
-{
-       return video_frame_allocator;
-}
-
-void set_video_frame_allocator(FrameAllocator *allocator)
-{
-       video_frame_allocator = allocator;
-}
-
-FrameAllocator *get_audio_frame_allocator()
-{
-       return audio_frame_allocator;
-}
-
-void set_audio_frame_allocator(FrameAllocator *allocator)
-{
-       audio_frame_allocator = allocator;
-}
-
-void set_frame_callback(frame_callback_t callback)
-{
-       frame_callback = callback;
-}
-
-void start_bm_capture()
+void BMUSBCapture::start_bm_capture()
 {
        if (video_frame_allocator == nullptr) {
                set_video_frame_allocator(new MallocFrameAllocator(FRAME_SIZE));  // FIXME: leak.
@@ -622,7 +575,7 @@ void start_bm_capture()
        if (audio_frame_allocator == nullptr) {
                set_audio_frame_allocator(new MallocFrameAllocator(65536));  // FIXME: leak.
        }
-       thread(dequeue_thread).detach();
+       thread(&BMUSBCapture::dequeue_thread, this).detach();
 
        int rc;
        struct libusb_transfer *xfr;
@@ -904,6 +857,7 @@ void start_bm_capture()
            LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN, /*request=*/214, /*value=*/0,
                /*index=*/44, /*length=*/4);
        libusb_fill_control_transfer(xfr, devh, cmdbuf, cb_xfr, &completed, 0);
+       xfr->user_data = this;
        libusb_submit_transfer(xfr);
 
        // set up an asynchronous transfer of register 24
@@ -915,6 +869,7 @@ void start_bm_capture()
            LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN, /*request=*/214, /*value=*/0,
                /*index=*/24, /*length=*/4);
        libusb_fill_control_transfer(xfr, devh, cmdbuf2, cb_xfr, &completed2, 0);
+       xfr->user_data = this;
        libusb_submit_transfer(xfr);
 #endif
 
@@ -927,6 +882,7 @@ void start_bm_capture()
            LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN, /*request=*/214, /*value=*/0,
                /*index=*/current_register, /*length=*/4);
        libusb_fill_control_transfer(xfr, devh, cmdbuf3, cb_xfr, &completed3, 0);
+       xfr->user_data = this;
        //libusb_submit_transfer(xfr);
 
        audiofp = fopen("audio.raw", "wb");
@@ -967,6 +923,7 @@ void start_bm_capture()
                        libusb_fill_iso_transfer(xfr, devh, ep, buf, num_bytes,
                                num_iso_pack, cb_xfr, nullptr, 0);
                        libusb_set_iso_packet_lengths(xfr, size);
+                       xfr->user_data = this;
                        iso_xfrs.push_back(xfr);
                }
        }
@@ -985,7 +942,8 @@ void start_bm_capture()
                }
        }
 
-       usb_thread = thread(usb_thread_func);
+       should_quit = false;
+       usb_thread = thread(&BMUSBCapture::usb_thread_func, this);
 
 
 #if 0
@@ -998,7 +956,7 @@ out:
 #endif
 }
 
-void stop_bm_capture()
+void BMUSBCapture::stop_bm_capture()
 {
        should_quit = true;
        usb_thread.join();

diff --git a/bmusb.h b/bmusb.h
index 311248e5fddb0864b6ce3dfbf01b775474413419..e0531c2c3f552543b81b48a225b396e4b7974c67 100644 (file)
--- a/bmusb.h
+++ b/bmusb.h
@@ -2,7 +2,12 @@
 #define _BMUSB_H
 
 #include <stdint.h>
+#include <atomic>
+#include <condition_variable>
+#include <deque>
 #include <functional>
+#include <mutex>
+#include <thread>
 
 // An interface for frame allocators; if you do not specify one
 // (using set_video_frame_allocator), a default one that pre-allocates
@@ -52,14 +57,74 @@ typedef std::function<void(uint16_t timecode,
                            FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)>
        frame_callback_t;
 
-void set_video_frame_allocator(FrameAllocator *allocator);  // Does not take ownership.
-FrameAllocator *get_video_frame_allocator();
+// The actual capturing class, representing capture from a single card.
+class BMUSBCapture {
+ public:
+       // Does not take ownership.
+       void set_video_frame_allocator(FrameAllocator *allocator)
+       {
+               video_frame_allocator = allocator;
+       }
+
+       FrameAllocator *get_video_frame_allocator()
+       {
+               return video_frame_allocator;
+       }
+
+       // Does not take ownership.
+       void set_audio_frame_allocator(FrameAllocator *allocator)
+       {
+               audio_frame_allocator = allocator;
+       }
+
+       FrameAllocator *get_audio_frame_allocator()
+       {
+               return audio_frame_allocator;
+       }
+
+       void set_frame_callback(frame_callback_t callback)
+       {
+               frame_callback = callback;
+       }
+
+       void start_bm_capture();
+       void stop_bm_capture();
+
+ private:
+       struct QueuedFrame {
+               uint16_t timecode;
+               uint16_t format;
+               FrameAllocator::Frame frame;
+       };
 
-void set_audio_frame_allocator(FrameAllocator *allocator);  // Does not take ownership.
-FrameAllocator *get_audio_frame_allocator();
+       void start_new_audio_block(const uint8_t *start);
+       void start_new_frame(const uint8_t *start);
 
-void set_frame_callback(frame_callback_t callback);
-void start_bm_capture();
-void stop_bm_capture();
+       void queue_frame(uint16_t format, uint16_t timecode, FrameAllocator::Frame frame, std::deque<QueuedFrame> *q);
+       void dequeue_thread();
+
+       void usb_thread_func();
+       static void cb_xfr(struct libusb_transfer *xfr);
+
+       FrameAllocator::Frame current_video_frame;
+       FrameAllocator::Frame current_audio_frame;
+
+       std::mutex queue_lock;
+       std::condition_variable queues_not_empty;
+       std::deque<QueuedFrame> pending_video_frames;
+       std::deque<QueuedFrame> pending_audio_frames;
+
+       std::thread usb_thread;
+       std::atomic<bool> should_quit;
+
+       FrameAllocator *video_frame_allocator = nullptr;
+       FrameAllocator *audio_frame_allocator = nullptr;
+       frame_callback_t frame_callback = nullptr;
+
+       int current_register = 0;
+
+       static constexpr int NUM_BMUSB_REGISTERS = 60;
+       uint8_t register_file[NUM_BMUSB_REGISTERS];
+};
 
 #endif

diff --git a/main.cpp b/main.cpp
index a605b1a75c208cc790d5d2eaac2d898732d5f2db..df70a65991333bf946b7cae1826ccbaae2d1e7bf 100644 (file)
--- a/main.cpp
+++ b/main.cpp
@@ -3,6 +3,8 @@
 #include "bmusb.h"
 
 using namespace std;
+       
+BMUSBCapture *usb;
 
 void check_frame_stability(uint16_t timecode,
                            FrameAllocator::Frame video_frame, size_t video_offset, uint16_t video_format,
@@ -30,14 +32,15 @@ void check_frame_stability(uint16_t timecode,
        last_video_bytes = video_frame.len - video_offset;
        last_audio_bytes = audio_frame.len - audio_offset;
 
-       get_video_frame_allocator()->release_frame(video_frame);
-       get_audio_frame_allocator()->release_frame(audio_frame);
+       usb->get_video_frame_allocator()->release_frame(video_frame);
+       usb->get_audio_frame_allocator()->release_frame(audio_frame);
 }
 
 int main(int argc, char **argv)
 {
-       set_frame_callback(check_frame_stability);
-       start_bm_capture();
+       usb = new BMUSBCapture;
+       usb->set_frame_callback(check_frame_stability);
+       usb->start_bm_capture();
        sleep(1000000);
 }