1 #define GL_GLEXT_PROTOTYPES
3 #include "video_widget.h"
15 #include <libavcodec/avcodec.h>
16 #include <libavformat/avformat.h>
17 #include <libavutil/avutil.h>
18 #include <libavutil/error.h>
19 #include <libavutil/frame.h>
20 #include <libavutil/imgutils.h>
21 #include <libavutil/mem.h>
22 #include <libavutil/pixfmt.h>
23 #include <libavutil/opt.h>
24 #include <libswscale/swscale.h>
31 #include <unordered_set>
33 #include "post_to_main_thread.h"
35 #include <QOpenGLFunctions>
36 #include <QWheelEvent>
37 #include <QMouseEvent>
38 #include <QMouseEvent>
39 #include <QHBoxLayout>
41 #define BUFFER_OFFSET(i) ((char *)nullptr + (i))
44 using namespace std::chrono;
48 bool is_full_range(const AVPixFmtDescriptor *desc)
50 // This is horrible, but there's no better way that I know of.
51 return (strchr(desc->name, 'j') != nullptr);
54 AVPixelFormat decide_dst_format(AVPixelFormat src_format)
56 // If this is a non-Y'CbCr format, just convert to 4:4:4 Y'CbCr
57 // and be done with it. It's too strange to spend a lot of time on.
58 // (Let's hope there's no alpha.)
59 const AVPixFmtDescriptor *src_desc = av_pix_fmt_desc_get(src_format);
60 if (src_desc == nullptr ||
61 src_desc->nb_components != 3 ||
62 (src_desc->flags & AV_PIX_FMT_FLAG_RGB)) {
63 return AV_PIX_FMT_YUV444P;
66 // The best for us would be Cb and Cr together if possible,
67 // but FFmpeg doesn't support that except in the special case of
68 // NV12, so we need to go to planar even for the case of NV12.
69 // Thus, look for the closest (but no worse) 8-bit planar Y'CbCr format
70 // that matches in color range. (This will also include the case of
71 // the source format already being acceptable.)
72 bool src_full_range = is_full_range(src_desc);
73 const char *best_format = "yuv444p";
74 unsigned best_score = numeric_limits<unsigned>::max();
75 for (const AVPixFmtDescriptor *desc = av_pix_fmt_desc_next(nullptr);
77 desc = av_pix_fmt_desc_next(desc)) {
78 // Find planar Y'CbCr formats only.
79 if (desc->nb_components != 3) continue;
80 if (desc->flags & AV_PIX_FMT_FLAG_RGB) continue;
81 if (!(desc->flags & AV_PIX_FMT_FLAG_PLANAR)) continue;
82 if (desc->comp[0].plane != 0 ||
83 desc->comp[1].plane != 1 ||
84 desc->comp[2].plane != 2) continue;
86 // 8-bit formats only.
87 if (desc->flags & AV_PIX_FMT_FLAG_BE) continue;
88 if (desc->comp[0].depth != 8) continue;
90 // Same or better chroma resolution only.
91 int chroma_w_diff = src_desc->log2_chroma_w - desc->log2_chroma_w;
92 int chroma_h_diff = src_desc->log2_chroma_h - desc->log2_chroma_h;
93 if (chroma_w_diff < 0 || chroma_h_diff < 0)
96 // Matching full/limited range only.
97 if (is_full_range(desc) != src_full_range)
100 // Pick something with as little excess chroma resolution as possible.
101 unsigned score = (1 << (chroma_w_diff)) << chroma_h_diff;
102 if (score < best_score) {
104 best_format = desc->name;
107 return av_get_pix_fmt(best_format);
112 bool VideoWidget::process_queued_commands(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, int video_stream_index, bool *seeked)
114 // Process any queued commands from other threads.
115 vector<QueuedCommand> commands;
117 lock_guard<mutex> lock(queue_mu);
118 swap(commands, command_queue);
121 for (const QueuedCommand &cmd : commands) {
122 switch (cmd.command) {
123 case QueuedCommand::PAUSE:
126 case QueuedCommand::RESUME:
128 pts_origin = last_pts;
129 start = next_frame_start = steady_clock::now();
131 case QueuedCommand::SEEK:
132 case QueuedCommand::SEEK_ABSOLUTE:
138 // Combine all seeks into one big one. (There are edge cases where this is probably
139 // subtly wrong, but we'll live with it.)
140 int64_t base_pts = last_pts;
141 int64_t relative_seek_ms = 0;
142 int64_t relative_seek_frames = 0;
143 for (const QueuedCommand &cmd : commands) {
144 if (cmd.command == QueuedCommand::SEEK) {
145 relative_seek_ms += cmd.relative_seek_ms;
146 relative_seek_frames += cmd.relative_seek_frames;
147 } else if (cmd.command == QueuedCommand::SEEK_ABSOLUTE) {
148 base_pts = av_rescale_q(cmd.seek_ms, AVRational{ 1, 1000 }, video_timebase);
149 relative_seek_ms = 0;
150 relative_seek_frames = 0;
153 int64_t relative_seek_pts = av_rescale_q(relative_seek_ms, AVRational{ 1, 1000 }, video_timebase);
154 if (relative_seek_ms != 0 && relative_seek_pts == 0) {
155 // Just to be sure rounding errors don't move us into nothingness.
156 relative_seek_pts = (relative_seek_ms > 0) ? 1 : -1;
158 int64_t goal_pts = base_pts + relative_seek_pts;
159 if (goal_pts != last_pts || relative_seek_frames < 0) {
160 avcodec_flush_buffers(video_codec_ctx);
161 queued_frames.clear();
163 // Seek to the last keyframe before this point.
164 int64_t seek_pts = goal_pts;
165 if (relative_seek_frames < 0) {
166 // If we're frame-skipping backwards, add 100 ms of slop for each frame
167 // so we're fairly certain we are able to see the ones we want.
168 seek_pts -= av_rescale_q(-relative_seek_frames, AVRational{ 1, 10 }, video_timebase);
170 av_seek_frame(format_ctx, video_stream_index, seek_pts, AVSEEK_FLAG_BACKWARD);
172 // Decode frames until EOF, or until we see something past our seek point.
173 std::deque<AVFrameWithDeleter> queue;
176 AVFrameWithDeleter frame = decode_frame(format_ctx, video_codec_ctx,
177 pathname, video_stream_index, &error);
178 if (frame == nullptr || error) {
182 int64_t frame_pts = frame->pts;
183 if (relative_seek_frames < 0) {
184 // Buffer this frame; don't display it unless we know it's the Nth-latest.
185 queue.push_back(std::move(frame));
186 if (queue.size() > uint64_t(-relative_seek_frames) + 1) {
190 if (frame_pts >= goal_pts) {
191 if (relative_seek_frames > 0) {
192 --relative_seek_frames;
194 if (relative_seek_frames < 0) {
195 // Hope we have the right amount.
196 // The rest will remain in the queue for when we play forward again.
197 frame = std::move(queue.front());
199 queued_frames = std::move(queue);
201 video_window->set_current_frame(make_video_frame(frame.get()));
203 store_pts(frame->pts);
209 // NOTE: We keep pause status as-is.
211 pts_origin = last_pts;
212 start = next_frame_start = last_frame = steady_clock::now();
216 } else if (relative_seek_frames > 0) {
217 // The base PTS is fine, we only need to skip a few frames forwards.
218 while (relative_seek_frames > 1) {
219 // Eat a frame (ignore errors).
221 decode_frame(format_ctx, video_codec_ctx, pathname, video_stream_index, &error);
222 --relative_seek_frames;
225 // Display the last one.
227 AVFrameWithDeleter frame = decode_frame(format_ctx, video_codec_ctx,
228 pathname, video_stream_index, &error);
229 if (frame == nullptr || error) {
232 video_window->set_current_frame(make_video_frame(frame.get()));
234 store_pts(frame->pts);
239 VideoWidget::VideoWidget(QWidget *parent)
241 video_window(new VideoWindow(this)) {
242 setLayout(new QHBoxLayout);
243 layout()->addWidget(QWidget::createWindowContainer(video_window));
246 connect(video_window, &VideoWindow::mouse_wheel, this, &VideoWidget::wheelEvent);
247 connect(video_window, &VideoWindow::mouse_pressed, this, &VideoWidget::mousePressEvent);
248 connect(video_window, &VideoWindow::mouse_released, this, &VideoWidget::mouseReleaseEvent);
249 connect(video_window, &VideoWindow::mouse_moved, this, &VideoWidget::mouseMoveEvent);
252 GLuint compile_shader(const string &shader_src, GLenum type)
254 GLuint obj = glCreateShader(type);
255 const GLchar* source[] = { shader_src.data() };
256 const GLint length[] = { (GLint)shader_src.size() };
257 glShaderSource(obj, 1, source, length);
258 glCompileShader(obj);
260 GLchar info_log[4096];
261 GLsizei log_length = sizeof(info_log) - 1;
262 glGetShaderInfoLog(obj, log_length, &log_length, info_log);
263 info_log[log_length] = 0;
264 if (strlen(info_log) > 0) {
265 fprintf(stderr, "Shader compile log: %s\n", info_log);
269 glGetShaderiv(obj, GL_COMPILE_STATUS, &status);
270 if (status == GL_FALSE) {
271 // Add some line numbers to easier identify compile errors.
272 string src_with_lines = "/* 1 */ ";
274 for (char ch : shader_src) {
275 src_with_lines.push_back(ch);
278 snprintf(buf, sizeof(buf), "/* %3zu */ ", ++lineno);
279 src_with_lines += buf;
283 fprintf(stderr, "Failed to compile shader:\n%s\n", src_with_lines.c_str());
290 void VideoWindow::initializeGL()
293 glDisable(GL_DEPTH_TEST);
294 glDepthMask(GL_FALSE);
295 glCreateTextures(GL_TEXTURE_2D, 3, tex);
297 ycbcr_vertex_shader = compile_shader(R"(
300 layout(location = 0) in vec2 position;
301 layout(location = 1) in vec2 texcoord;
306 // The result of glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0) is:
308 // 2.000 0.000 0.000 -1.000
309 // 0.000 2.000 0.000 -1.000
310 // 0.000 0.000 -2.000 -1.000
311 // 0.000 0.000 0.000 1.000
312 gl_Position = vec4(2.0 * position.x - 1.0, 2.0 * position.y - 1.0, -1.0, 1.0);
316 )", GL_VERTEX_SHADER);
317 ycbcr_fragment_shader = compile_shader(R"(
320 layout(location = 0) uniform sampler2D tex_y;
321 layout(location = 1) uniform sampler2D tex_cb;
322 layout(location = 2) uniform sampler2D tex_cr;
323 layout(location = 3) uniform vec2 cbcr_offset;
328 // Computed statically by Movit, for limited-range BT.709.
329 // (We don't check whether the input could be BT.601 or BT.2020 currently, or full-range)
330 const mat3 inv_ycbcr_matrix = mat3(
331 1.16438f, 1.16438f, 1.16438f,
332 0.0f, -0.21325f, 2.11240f,
333 1.79274f, -0.53291f, 0.0f
338 if (tc.x < 0.0 || tc.x > 1.0 || tc.y < 0.0 || tc.y > 1.0) {
339 FragColor.rgba = vec4(0.0f, 0.0f, 0.0f, 1.0f);
344 ycbcr.r = texture(tex_y, tc).r;
345 ycbcr.g = texture(tex_cb, tc + cbcr_offset).r;
346 ycbcr.b = texture(tex_cr, tc + cbcr_offset).r;
347 ycbcr -= vec3(16.0f / 255.0f, 128.0f / 255.0f, 128.0f / 255.0f);
348 FragColor.rgb = inv_ycbcr_matrix * ycbcr;
351 )", GL_FRAGMENT_SHADER);
352 ycbcr_program = glCreateProgram();
353 glAttachShader(ycbcr_program, ycbcr_vertex_shader);
354 glAttachShader(ycbcr_program, ycbcr_fragment_shader);
355 glLinkProgram(ycbcr_program);
358 glGetProgramiv(ycbcr_program, GL_LINK_STATUS, &success);
359 if (success == GL_FALSE) {
360 GLchar error_log[1024] = {0};
361 glGetProgramInfoLog(ycbcr_program, 1024, nullptr, error_log);
362 fprintf(stderr, "Error linking program: %s\n", error_log);
366 glCreateSamplers(1, &bilinear_sampler);
367 glSamplerParameteri(bilinear_sampler, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
368 glSamplerParameteri(bilinear_sampler, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
369 glSamplerParameteri(bilinear_sampler, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
370 glSamplerParameteri(bilinear_sampler, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
373 void VideoWindow::resizeGL(int w, int h)
375 glViewport(0, 0, w, h);
376 display_aspect = double(w) / h;
379 int num_levels(GLuint width, GLuint height)
382 while (width > 1 || height > 1) {
383 width = max(width / 2, 1u);
384 height = max(height / 2, 1u);
390 void VideoWindow::paintGL()
392 std::shared_ptr<VideoWidget::Frame> frame;
394 lock_guard lock(current_frame_mu);
395 frame = current_frame;
397 if (frame == nullptr) {
398 glClear(GL_COLOR_BUFFER_BIT);
402 glUseProgram(ycbcr_program);
403 if (frame->width != last_width || frame->height != last_height) {
404 glTextureStorage2D(tex[0], num_levels(frame->width, frame->height), GL_R8, frame->width, frame->height);
406 if (frame->chroma_width != last_chroma_width || frame->chroma_height != last_chroma_height) {
407 for (GLuint num : { tex[1], tex[2] }) {
408 glTextureStorage2D(num, num_levels(frame->chroma_width, frame->chroma_height), GL_R8, frame->chroma_width, frame->chroma_height);
412 glBindBuffer(GL_PIXEL_UNPACK_BUFFER, frame->pbo);
414 if (frame->need_flush_len > 0) {
415 glFlushMappedNamedBufferRange(frame->pbo, 0, frame->need_flush_len);
416 frame->need_flush_len = 0;
419 glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
420 glTextureSubImage2D(tex[0], 0, 0, 0, frame->width, frame->height, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
421 glGenerateTextureMipmap(tex[0]);
423 glTextureSubImage2D(tex[1], 0, 0, 0, frame->chroma_width, frame->chroma_height, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(frame->width * frame->height));
424 glGenerateTextureMipmap(tex[1]);
426 glTextureSubImage2D(tex[2], 0, 0, 0, frame->chroma_width, frame->chroma_height, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(frame->width * frame->height + frame->chroma_width * frame->chroma_height));
427 glGenerateTextureMipmap(tex[2]);
429 glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
431 glBindTextureUnit(0, tex[0]);
432 glBindTextureUnit(1, tex[1]);
433 glBindTextureUnit(2, tex[2]);
434 glBindSampler(0, bilinear_sampler);
435 glBindSampler(1, bilinear_sampler);
436 glBindSampler(2, bilinear_sampler);
437 glProgramUniform1i(ycbcr_program, 0, 0);
438 glProgramUniform1i(ycbcr_program, 1, 1);
439 glProgramUniform1i(ycbcr_program, 2, 2);
440 glProgramUniform2f(ycbcr_program, 3, cbcr_offset[0], -cbcr_offset[1]);
447 double video_aspect = double(frame->width) / frame->height;
448 if (display_aspect > video_aspect) {
449 double extra_width = frame->height * display_aspect - frame->width;
450 tx1 = -0.5 * extra_width / frame->width;
451 tx2 = 1.0 + 0.5 * extra_width / frame->width;
452 } else if (display_aspect < video_aspect) {
453 double extra_height = frame->width / display_aspect - frame->height;
454 ty1 = -0.5 * extra_height / frame->height;
455 ty2 = 1.0 + 0.5 * extra_height / frame->height;
461 glVertexAttrib2f(1, tx1, ty1);
462 glVertex2f(zoom_matrix[2 * 3 + 0], zoom_matrix[2 * 3 + 1]);
465 glVertexAttrib2f(1, tx1, ty2);
466 glVertex2f(zoom_matrix[1 * 3 + 0] + zoom_matrix[2 * 3 + 0], zoom_matrix[1 * 3 + 1] + zoom_matrix[2 * 3 + 1]);
469 glVertexAttrib2f(1, tx2, ty2);
470 glVertex2f(zoom_matrix[0 * 3 + 0] + zoom_matrix[1 * 3 + 0] + zoom_matrix[2 * 3 + 0],
471 zoom_matrix[1 * 3 + 0] + zoom_matrix[1 * 3 + 1] + zoom_matrix[2 * 3 + 1]);
474 glVertexAttrib2f(1, tx2, ty1);
475 glVertex2f(zoom_matrix[0 * 3 + 0] + zoom_matrix[2 * 3 + 0],
476 zoom_matrix[1 * 3 + 0] + zoom_matrix[2 * 3 + 1]);
481 void VideoWindow::set_current_frame(shared_ptr<VideoWidget::Frame> new_frame)
484 lock_guard lock(current_frame_mu);
485 current_frame = std::move(new_frame);
490 void matmul3x3(const double a[9], const double b[9], double res[9])
492 for (int i = 0; i < 3; ++i) {
493 for (int j = 0; j < 3; ++j) {
495 for (int k = 0; k < 3; ++k) {
496 sum += a[i * 3 + k] * b[k * 3 + j];
498 res[i * 3 + j] = sum;
503 void VideoWidget::wheelEvent(QWheelEvent *event)
505 int delta = event->angleDelta().y();
509 double x = event->position().x() / width();
510 double y = 1.0 - event->position().y() / height();
511 double zoom = delta > 0 ? pow(1.005, delta) : pow(1/1.005, -delta);
513 const double inv_translation_matrix[9] = {
518 const double scale_matrix[9] = {
523 const double translation_matrix[9] = {
528 double tmp1[9], tmp2[9];
529 matmul3x3(zoom_matrix, inv_translation_matrix, tmp1);
530 matmul3x3(tmp1, scale_matrix, tmp2);
531 matmul3x3(tmp2, translation_matrix, zoom_matrix);
534 video_window->set_zoom_matrix(zoom_matrix);
538 void VideoWidget::mousePressEvent(QMouseEvent *e)
540 if (e->button() == Qt::BackButton) {
541 emit mouse_back_clicked();
542 } else if (e->button() == Qt::ForwardButton) {
543 emit mouse_forward_clicked();
544 } else if (e->button() == Qt::LeftButton) {
546 last_drag_x = e->position().x();
547 last_drag_y = e->position().y();
551 void VideoWidget::mouseReleaseEvent(QMouseEvent *e)
553 if (e->button() == Qt::LeftButton) {
558 void VideoWidget::mouseMoveEvent(QMouseEvent *e)
563 float dx = (e->position().x() - last_drag_x) / width();
564 float dy = (e->position().y() - last_drag_y) / height();
566 //zoom_matrix[6] += dx * zoom_matrix[0];
567 //zoom_matrix[7] += dy * zoom_matrix[4];
568 zoom_matrix[6] += dx;
569 zoom_matrix[7] -= dy;
571 video_window->set_zoom_matrix(zoom_matrix);
573 last_drag_x = e->position().x();
574 last_drag_y = e->position().y();
579 // Normalize the matrix so that we never get skew or similar,
580 // and also never can zoom or pan too far out.
581 void VideoWidget::fixup_zoom_matrix()
583 // Correct for any numerical errors (we know the matrix must be orthogonal
584 // and have zero rotation).
585 zoom_matrix[4] = zoom_matrix[0];
586 zoom_matrix[1] = zoom_matrix[2] = zoom_matrix[3] = zoom_matrix[5] = 0.0;
587 zoom_matrix[8] = 1.0;
589 // We can't zoom further out than 1:1. (Perhaps it would be nice to
590 // reuse the last zoom-in point to do this, but the center will have to do
592 if (zoom_matrix[0] < 1.0) {
593 const double zoom = 1.0 / zoom_matrix[0];
594 const double inv_translation_matrix[9] = {
599 const double scale_matrix[9] = {
604 const double translation_matrix[9] = {
609 double tmp1[9], tmp2[9];
610 matmul3x3(zoom_matrix, inv_translation_matrix, tmp1);
611 matmul3x3(tmp1, scale_matrix, tmp2);
612 matmul3x3(tmp2, translation_matrix, zoom_matrix);
615 // Looking at the points we'll draw with glVertex2f(), make sure none of them are
616 // inside the square (which would generally mean we've panned ourselves out-of-bounds).
617 // We simply adjust the translation, which is possible because we fixed scaling above.
618 zoom_matrix[6] = min(zoom_matrix[6], 0.0); // Left side (x=0).
619 zoom_matrix[7] = min(zoom_matrix[7], 0.0); // Bottom side (y=0).
620 zoom_matrix[6] = std::max(zoom_matrix[6], 1.0 - zoom_matrix[0]); // Right side (x=1).
621 zoom_matrix[7] = std::max(zoom_matrix[7], 1.0 - zoom_matrix[4]); // Top side (y=1).
624 bool VideoWidget::open(const string &filename)
631 while (running == STARTING) {
632 // Poor man's condition variable...
636 return (running != VIDEO_FILE_ERROR);
639 void VideoWidget::play()
641 if (running != NOT_RUNNING && running != VIDEO_FILE_ERROR) {
642 std::lock_guard<std::mutex> lock(queue_mu);
643 command_queue.push_back(QueuedCommand { QueuedCommand::RESUME });
644 producer_thread_should_quit.wakeup();
648 producer_thread_should_quit.unquit();
649 if (producer_thread.joinable()) {
650 producer_thread.join();
652 producer_thread = std::thread(&VideoWidget::producer_thread_func, this);
655 void VideoWidget::pause()
657 if (running == NOT_RUNNING || running == VIDEO_FILE_ERROR) {
660 std::lock_guard<std::mutex> lock(queue_mu);
661 command_queue.push_back(QueuedCommand { QueuedCommand::PAUSE });
662 producer_thread_should_quit.wakeup();
665 void VideoWidget::seek(int64_t relative_seek_ms)
667 if (running == NOT_RUNNING || running == VIDEO_FILE_ERROR) {
670 std::lock_guard<std::mutex> lock(queue_mu);
671 command_queue.push_back(QueuedCommand { QueuedCommand::SEEK, relative_seek_ms, 0, 0 });
672 producer_thread_should_quit.wakeup();
675 void VideoWidget::seek_frames(int64_t relative_seek_frames)
677 if (running == NOT_RUNNING || running == VIDEO_FILE_ERROR) {
680 std::lock_guard<std::mutex> lock(queue_mu);
681 command_queue.push_back(QueuedCommand { QueuedCommand::SEEK, 0, relative_seek_frames, 0 });
682 producer_thread_should_quit.wakeup();
685 void VideoWidget::seek_absolute(int64_t position_ms)
687 if (running == NOT_RUNNING || running == VIDEO_FILE_ERROR) {
690 std::lock_guard<std::mutex> lock(queue_mu);
691 command_queue.push_back(QueuedCommand { QueuedCommand::SEEK_ABSOLUTE, 0, 0, position_ms });
692 producer_thread_should_quit.wakeup();
695 void VideoWidget::stop()
697 if (running == NOT_RUNNING || running == VIDEO_FILE_ERROR) {
700 producer_thread_should_quit.quit();
701 producer_thread.join();
704 void VideoWidget::producer_thread_func()
706 if (!producer_thread_should_quit.should_quit()) {
707 if (!play_video(pathname)) {
708 running = VIDEO_FILE_ERROR;
710 running = NOT_RUNNING;
715 void VideoWidget::internal_rewind()
717 pts_origin = last_pts = 0;
719 start = next_frame_start = steady_clock::now();
722 template<AVHWDeviceType type>
723 AVPixelFormat get_hw_format(AVCodecContext *ctx, const AVPixelFormat *fmt)
725 bool found_config_of_right_type = false;
726 for (int i = 0;; ++i) { // Termination condition inside loop.
727 const AVCodecHWConfig *config = avcodec_get_hw_config(ctx->codec, i);
728 if (config == nullptr) { // End of list.
731 if (!(config->methods & AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX) ||
732 config->device_type != type) {
733 // Not interesting for us.
737 // We have a config of the right type, but does it actually support
738 // the pixel format we want? (Seemingly, FFmpeg's way of signaling errors
739 // is to just replace the pixel format with a software-decoded one,
741 found_config_of_right_type = true;
742 for (const AVPixelFormat *fmt_ptr = fmt; *fmt_ptr != -1; ++fmt_ptr) {
743 if (config->pix_fmt == *fmt_ptr) {
744 fprintf(stderr, "Initialized '%s' hardware decoding for codec '%s'.\n",
745 av_hwdevice_get_type_name(type), ctx->codec->name);
746 if (ctx->profile == FF_PROFILE_H264_BASELINE) {
747 fprintf(stderr, "WARNING: Stream claims to be H.264 Baseline, which is generally poorly supported in hardware decoders.\n");
748 fprintf(stderr, " Consider encoding it as Constrained Baseline, Main or High instead.\n");
749 fprintf(stderr, " Decoding might fail and fall back to software.\n");
751 return config->pix_fmt;
754 fprintf(stderr, "Decoder '%s' supports only these pixel formats:", ctx->codec->name);
755 unordered_set<AVPixelFormat> seen;
756 for (const AVPixelFormat *fmt_ptr = fmt; *fmt_ptr != -1; ++fmt_ptr) {
757 if (!seen.count(*fmt_ptr)) {
758 fprintf(stderr, " %s", av_get_pix_fmt_name(*fmt_ptr));
759 seen.insert(*fmt_ptr);
762 fprintf(stderr, " (wanted %s for hardware acceleration)\n", av_get_pix_fmt_name(config->pix_fmt));
766 if (!found_config_of_right_type) {
767 fprintf(stderr, "Decoder '%s' does not support device type '%s'.\n", ctx->codec->name, av_hwdevice_get_type_name(type));
770 // We found no VA-API formats, so take the first software format.
771 for (const AVPixelFormat *fmt_ptr = fmt; *fmt_ptr != -1; ++fmt_ptr) {
772 if ((av_pix_fmt_desc_get(*fmt_ptr)->flags & AV_PIX_FMT_FLAG_HWACCEL) == 0) {
773 fprintf(stderr, "Falling back to software format %s.\n", av_get_pix_fmt_name(*fmt_ptr));
778 // Fallback: Just return anything. (Should never really happen.)
782 AVFrameWithDeleter VideoWidget::decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx,
783 const std::string &pathname, int video_stream_index,
788 if (!queued_frames.empty()) {
789 AVFrameWithDeleter frame = std::move(queued_frames.front());
790 queued_frames.pop_front();
794 // Read packets until we have a frame or there are none left.
795 bool frame_finished = false;
796 AVFrameWithDeleter video_avframe = av_frame_alloc_unique();
799 AVPacket *pkt = av_packet_alloc();
800 unique_ptr<AVPacket, decltype(av_packet_unref)*> pkt_cleanup(
801 pkt, av_packet_unref);
804 if (av_read_frame(format_ctx, pkt) == 0) {
805 if (pkt->stream_index == video_stream_index) {
806 if (avcodec_send_packet(video_codec_ctx, pkt) < 0) {
807 fprintf(stderr, "%s: Cannot send packet to video codec.\n", pathname.c_str());
809 return AVFrameWithDeleter(nullptr);
813 eof = true; // Or error, but ignore that for the time being.
816 // Decode video, if we have a frame.
817 int err = avcodec_receive_frame(video_codec_ctx, video_avframe.get());
819 frame_finished = true;
821 } else if (err != AVERROR(EAGAIN)) {
822 fprintf(stderr, "%s: Cannot receive frame from video codec.\n", pathname.c_str());
824 return AVFrameWithDeleter(nullptr);
829 return video_avframe;
831 return AVFrameWithDeleter(nullptr);
834 int find_stream_index(AVFormatContext *ctx, AVMediaType media_type)
836 for (unsigned i = 0; i < ctx->nb_streams; ++i) {
837 if (ctx->streams[i]->codecpar->codec_type == media_type) {
844 steady_clock::time_point compute_frame_start(int64_t frame_pts, int64_t pts_origin, const AVRational &video_timebase, const steady_clock::time_point &origin, double rate)
846 const duration<double> pts((frame_pts - pts_origin) * double(video_timebase.num) / double(video_timebase.den));
847 return origin + duration_cast<steady_clock::duration>(pts / rate);
850 bool VideoWidget::play_video(const string &pathname)
852 queued_frames.clear();
853 AVFormatContextWithCloser format_ctx = avformat_open_input_unique(pathname.c_str(), /*fmt=*/nullptr,
854 /*options=*/nullptr);
855 if (format_ctx == nullptr) {
856 fprintf(stderr, "%s: Error opening file\n", pathname.c_str());
860 if (avformat_find_stream_info(format_ctx.get(), nullptr) < 0) {
861 fprintf(stderr, "%s: Error finding stream info\n", pathname.c_str());
865 int video_stream_index = find_stream_index(format_ctx.get(), AVMEDIA_TYPE_VIDEO);
866 if (video_stream_index == -1) {
867 fprintf(stderr, "%s: No video stream found\n", pathname.c_str());
871 // Open video decoder.
872 const AVCodecParameters *video_codecpar = format_ctx->streams[video_stream_index]->codecpar;
873 const AVCodec *video_codec = avcodec_find_decoder(video_codecpar->codec_id);
875 video_timebase = format_ctx->streams[video_stream_index]->time_base;
876 AVCodecContextWithDeleter video_codec_ctx = avcodec_alloc_context3_unique(nullptr);
877 if (avcodec_parameters_to_context(video_codec_ctx.get(), video_codecpar) < 0) {
878 fprintf(stderr, "%s: Cannot fill video codec parameters\n", pathname.c_str());
881 if (video_codec == nullptr) {
882 fprintf(stderr, "%s: Cannot find video decoder\n", pathname.c_str());
886 // Seemingly, it's not too easy to make something that just initializes
887 // “whatever goes”, so we don't get CUDA or VULKAN or whatever here
888 // without enumerating through several different types.
889 // VA-API and VDPAU will do for now. We prioritize VDPAU for the
890 // simple reason that there's a VA-API-via-VDPAU emulation for NVidia
891 // cards that seems to work, but just hangs when trying to transfer the frame.
893 // Note that we don't actually check codec support beforehand,
894 // so if you have a low-end VDPAU device but a high-end VA-API device,
895 // you lose out on the extra codec support from the latter.
896 AVBufferRef *hw_device_ctx = nullptr;
897 if (av_hwdevice_ctx_create(&hw_device_ctx, AV_HWDEVICE_TYPE_VDPAU, nullptr, nullptr, 0) >= 0) {
898 video_codec_ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx);
899 video_codec_ctx->get_format = get_hw_format<AV_HWDEVICE_TYPE_VDPAU>;
900 } else if (av_hwdevice_ctx_create(&hw_device_ctx, AV_HWDEVICE_TYPE_VAAPI, nullptr, nullptr, 0) >= 0) {
901 video_codec_ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx);
902 video_codec_ctx->get_format = get_hw_format<AV_HWDEVICE_TYPE_VAAPI>;
904 fprintf(stderr, "Failed to initialize VA-API or VDPAU for FFmpeg acceleration. Decoding video in software.\n");
907 if (avcodec_open2(video_codec_ctx.get(), video_codec, nullptr) < 0) {
908 fprintf(stderr, "%s: Cannot open video decoder\n", pathname.c_str());
911 unique_ptr<AVCodecContext, decltype(avcodec_close)*> video_codec_ctx_cleanup(
912 video_codec_ctx.get(), avcodec_close);
919 int consecutive_errors = 0;
921 while (!producer_thread_should_quit.should_quit()) {
922 if (process_queued_commands(format_ctx.get(), video_codec_ctx.get(), video_stream_index, /*seeked=*/nullptr)) {
926 producer_thread_should_quit.sleep_for(hours(1));
931 AVFrameWithDeleter frame = decode_frame(format_ctx.get(), video_codec_ctx.get(),
932 pathname, video_stream_index, &error);
934 if (++consecutive_errors >= 100) {
935 fprintf(stderr, "More than 100 consecutive video frames, aborting playback.\n");
941 consecutive_errors = 0;
943 if (frame == nullptr) {
948 // Sleep until it's time to present this frame.
950 if (last_pts == 0 && pts_origin == 0) {
951 pts_origin = frame->pts;
953 steady_clock::time_point now = steady_clock::now();
954 next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
956 if (duration<double>(now - next_frame_start).count() >= 0.1) {
957 // If we don't have enough CPU to keep up, or if we have a live stream
958 // where the initial origin was somehow wrong, we could be behind indefinitely.
959 fprintf(stderr, "%s: Playback %.0f ms behind, resetting time scale\n",
961 1e3 * duration<double>(now - next_frame_start).count());
962 pts_origin = frame->pts;
963 start = next_frame_start = now;
965 bool finished_wakeup;
966 finished_wakeup = producer_thread_should_quit.sleep_until(next_frame_start);
967 if (finished_wakeup) {
968 video_window->set_current_frame(make_video_frame(frame.get()));
969 last_frame = steady_clock::now();
973 if (producer_thread_should_quit.should_quit()) break;
976 if (process_queued_commands(format_ctx.get(), video_codec_ctx.get(), video_stream_index, &seeked)) {
981 // Just paused, so present the frame immediately and then go into deep sleep.
982 video_window->set_current_frame(make_video_frame(frame.get()));
983 last_frame = steady_clock::now();
988 // If we just seeked, drop this frame on the floor and be done.
994 store_pts(frame->pts);
999 void VideoWidget::store_pts(int64_t pts)
1002 last_position = lrint(pts * double(video_timebase.num) / double(video_timebase.den) * 1000);
1003 post_to_main_thread([this, last_position{last_position.load()}] {
1004 emit position_changed(last_position);
1008 // Taken from Movit (see the comment there for explanation)
1009 float compute_chroma_offset(float pos, unsigned subsampling_factor, unsigned resolution)
1011 float local_chroma_pos = (0.5 + pos * (subsampling_factor - 1)) / subsampling_factor;
1012 if (fabs(local_chroma_pos - 0.5) < 1e-10) {
1013 // x + (-0) can be optimized away freely, as opposed to x + 0.
1016 return (0.5 - local_chroma_pos) / resolution;
1020 shared_ptr<VideoWidget::Frame> VideoWidget::alloc_frame(unsigned width, unsigned height, unsigned chroma_width, unsigned chroma_height)
1022 lock_guard lock(freelist_mu);
1023 for (auto it = frame_freelist.begin(); it != frame_freelist.end(); ++it) {
1024 if ((*it)->width == width &&
1025 (*it)->height == height &&
1026 (*it)->chroma_width == chroma_width &&
1027 (*it)->chroma_height == chroma_height) {
1029 frame_freelist.erase(it);
1030 return shared_ptr<Frame>{frame, free_frame};
1034 Frame *frame = new Frame;
1035 frame->owner = this;
1036 frame->width = width;
1037 frame->height = height;
1038 frame->chroma_width = chroma_width;
1039 frame->chroma_height = chroma_height;
1041 size_t len = frame->width * frame->height + 2 * frame->chroma_width * frame->chroma_height;
1043 while (!video_window->isValid()) {
1049 condition_variable done_cv;
1052 post_to_main_thread([this, &frame, len, &done, &mu, &done_cv]{
1053 video_window->makeCurrent();
1054 glCreateBuffers(1, &frame->pbo);
1055 glNamedBufferStorage(frame->pbo, len, nullptr, GL_MAP_WRITE_BIT | GL_MAP_PERSISTENT_BIT);
1056 frame->data = (uint8_t *)glMapNamedBufferRange(frame->pbo, 0, len, GL_MAP_WRITE_BIT | GL_MAP_FLUSH_EXPLICIT_BIT | GL_MAP_PERSISTENT_BIT);
1057 video_window->doneCurrent();
1059 lock_guard lock(mu);
1061 done_cv.notify_all();
1064 unique_lock lock(mu);
1065 done_cv.wait(lock, [&done]{ return done; });
1068 return shared_ptr<Frame>{frame, free_frame};
1071 void VideoWidget::free_frame(VideoWidget::Frame *frame)
1073 VideoWidget *self = frame->owner;
1074 lock_guard lock(self->freelist_mu);
1075 if (self->frame_freelist.size() >= 16) {
1076 GLuint pbo = frame->pbo;
1077 post_to_main_thread([self, pbo]{
1078 self->video_window->makeCurrent();
1079 glUnmapNamedBuffer(pbo);
1080 glDeleteBuffers(1, &pbo);
1081 self->video_window->doneCurrent();
1083 delete self->frame_freelist.front();
1084 self->frame_freelist.pop_front();
1086 self->frame_freelist.push_back(frame);
1089 shared_ptr<VideoWidget::Frame> VideoWidget::make_video_frame(const AVFrame *frame)
1091 AVFrameWithDeleter sw_frame;
1093 if (frame->format == AV_PIX_FMT_VAAPI ||
1094 frame->format == AV_PIX_FMT_VDPAU) {
1095 // Get the frame down to the CPU. (TODO: See if we can keep it
1096 // on the GPU all the way, since it will be going up again later.
1097 // However, this only works if the OpenGL GPU is the same one.)
1098 sw_frame = av_frame_alloc_unique();
1099 int err = av_hwframe_transfer_data(sw_frame.get(), frame, 0);
1101 fprintf(stderr, "%s: Cannot transfer hardware video frame to software.\n", pathname.c_str());
1103 sw_frame->pts = frame->pts;
1104 sw_frame->pkt_duration = frame->pkt_duration;
1105 frame = sw_frame.get();
1109 if (sws_ctx == nullptr ||
1110 sws_last_width != frame->width ||
1111 sws_last_height != frame->height ||
1112 sws_last_src_format != frame->format) {
1113 sws_dst_format = decide_dst_format(AVPixelFormat(frame->format));
1115 sws_getContext(frame->width, frame->height, AVPixelFormat(frame->format),
1116 frame->width, frame->height, sws_dst_format,
1117 SWS_BICUBIC, nullptr, nullptr, nullptr));
1118 sws_last_width = frame->width;
1119 sws_last_height = frame->height;
1120 sws_last_src_format = frame->format;
1122 if (sws_ctx == nullptr) {
1123 fprintf(stderr, "Could not create scaler context\n");
1127 uint8_t *pic_data[4] = { nullptr, nullptr, nullptr, nullptr };
1128 int linesizes[4] = { 0, 0, 0, 0 };
1129 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(sws_dst_format);
1131 shared_ptr<Frame> video_frame = alloc_frame(
1134 AV_CEIL_RSHIFT(int(frame->width), desc->log2_chroma_w),
1135 AV_CEIL_RSHIFT(int(frame->height), desc->log2_chroma_h));
1137 // We always assume left chroma placement for now.
1138 video_window->set_cbcr_offset(
1139 compute_chroma_offset(0.0f, 1 << desc->log2_chroma_w, video_frame->chroma_width),
1140 compute_chroma_offset(0.5f, 1 << desc->log2_chroma_h, video_frame->chroma_height)
1143 pic_data[0] = video_frame->data;
1144 linesizes[0] = frame->width;
1146 pic_data[1] = pic_data[0] + frame->width * frame->height;
1147 linesizes[1] = video_frame->chroma_width;
1149 pic_data[2] = pic_data[1] + video_frame->chroma_width * video_frame->chroma_height;
1150 linesizes[2] = video_frame->chroma_width;
1152 sws_scale(sws_ctx.get(), frame->data, frame->linesize, 0, frame->height, pic_data, linesizes);
1154 video_frame->need_flush_len = video_frame->width * video_frame->height + 2 * video_frame->chroma_width * video_frame->chroma_height;