} // namespace
FFmpegCapture::FFmpegCapture(const string &filename, unsigned width, unsigned height)
- : filename(filename), width(width), height(height)
+ : filename(filename), width(width), height(height), video_timebase{1, 1}
{
// Not really used for anything.
description = "Video: " + filename;
}
const AVCodecParameters *codecpar = format_ctx->streams[video_stream_index]->codecpar;
- AVRational video_timebase = format_ctx->streams[video_stream_index]->time_base;
+ video_timebase = format_ctx->streams[video_stream_index]->time_base;
AVCodecContextWithDeleter codec_ctx = avcodec_alloc_context3_unique(nullptr);
if (avcodec_parameters_to_context(codec_ctx.get(), codecpar) < 0) {
fprintf(stderr, "%s: Cannot fill codec parameters\n", pathname.c_str());
internal_rewind();
- unique_ptr<SwsContext, decltype(sws_freeContext)*> sws_ctx(nullptr, sws_freeContext);
- int sws_last_width = -1, sws_last_height = -1, sws_last_src_format = -1;
- AVPixelFormat sws_dst_format = AVPixelFormat(-1); // In practice, always initialized.
-
// Main loop.
while (!producer_thread_should_quit.should_quit()) {
- if (process_queued_commands(format_ctx.get(), pathname, last_modified)) {
+ if (process_queued_commands(format_ctx.get(), pathname, last_modified, /*rewound=*/nullptr)) {
return true;
}
continue;
}
- if (sws_ctx == nullptr ||
- sws_last_width != frame->width ||
- sws_last_height != frame->height ||
- sws_last_src_format != frame->format) {
- sws_dst_format = decide_dst_format(AVPixelFormat(frame->format), pixel_format);
- sws_ctx.reset(
- sws_getContext(frame->width, frame->height, AVPixelFormat(frame->format),
- width, height, sws_dst_format,
- SWS_BICUBIC, nullptr, nullptr, nullptr));
- sws_last_width = frame->width;
- sws_last_height = frame->height;
- sws_last_src_format = frame->format;
- }
- if (sws_ctx == nullptr) {
- fprintf(stderr, "%s: Could not create scaler context\n", pathname.c_str());
+ VideoFormat video_format = construct_video_format(frame.get(), video_timebase);
+ FrameAllocator::Frame video_frame = make_video_frame(frame.get(), pathname, &error);
+ if (error) {
return false;
}
- VideoFormat video_format;
- video_format.width = width;
- video_format.height = height;
- if (pixel_format == bmusb::PixelFormat_8BitBGRA) {
- video_format.stride = width * 4;
- } else {
- assert(pixel_format == bmusb::PixelFormat_8BitYCbCrPlanar);
- video_format.stride = width;
- }
- video_format.frame_rate_nom = video_timebase.den;
- video_format.frame_rate_den = av_frame_get_pkt_duration(frame.get()) * video_timebase.num;
- if (video_format.frame_rate_nom == 0 || video_format.frame_rate_den == 0) {
- // Invalid frame rate.
- video_format.frame_rate_nom = 60;
- video_format.frame_rate_den = 1;
- }
- video_format.has_signal = true;
- video_format.is_connected = true;
-
- next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
- last_pts = frame->pts;
-
- FrameAllocator::Frame video_frame = video_frame_allocator->alloc_frame();
- if (video_frame.data != nullptr) {
- uint8_t *pic_data[4] = { nullptr, nullptr, nullptr, nullptr };
- int linesizes[4] = { 0, 0, 0, 0 };
- if (pixel_format == bmusb::PixelFormat_8BitBGRA) {
- pic_data[0] = video_frame.data;
- linesizes[0] = video_format.stride;
- video_frame.len = video_format.stride * height;
- } else {
- assert(pixel_format == bmusb::PixelFormat_8BitYCbCrPlanar);
- const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(sws_dst_format);
-
- int chroma_width = AV_CEIL_RSHIFT(int(width), desc->log2_chroma_w);
- int chroma_height = AV_CEIL_RSHIFT(int(height), desc->log2_chroma_h);
-
- pic_data[0] = video_frame.data;
- linesizes[0] = width;
-
- pic_data[1] = pic_data[0] + width * height;
- linesizes[1] = chroma_width;
-
- pic_data[2] = pic_data[1] + chroma_width * chroma_height;
- linesizes[2] = chroma_width;
-
- video_frame.len = width * height + 2 * chroma_width * chroma_height;
-
- current_frame_ycbcr_format = decode_ycbcr_format(desc, frame.get());
- }
- sws_scale(sws_ctx.get(), frame->data, frame->linesize, 0, frame->height, pic_data, linesizes);
- video_frame.received_timestamp = next_frame_start;
- }
-
FrameAllocator::Frame audio_frame;
AudioFormat audio_format;
audio_format.bits_per_sample = 32;
audio_format.num_channels = 8;
- producer_thread_should_quit.sleep_until(next_frame_start);
- frame_callback(timecode++,
- video_frame, 0, video_format,
- audio_frame, 0, audio_format);
+ for ( ;; ) {
+ next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
+ video_frame.received_timestamp = next_frame_start;
+ bool finished_wakeup = producer_thread_should_quit.sleep_until(next_frame_start);
+ if (finished_wakeup) {
+ frame_callback(timecode++,
+ video_frame, 0, video_format,
+ audio_frame, 0, audio_format);
+ break;
+ } else {
+ if (producer_thread_should_quit.should_quit()) break;
+
+ bool rewound = false;
+ if (process_queued_commands(format_ctx.get(), pathname, last_modified, &rewound)) {
+ return true;
+ }
+ // If we just rewound, drop this frame on the floor and be done.
+ if (rewound) {
+ video_frame_allocator->release_frame(video_frame);
+ break;
+ }
+ // OK, we didn't, so probably a rate change. Recalculate next_frame_start,
+ // but if it's now in the past, we'll reset the origin, so that we don't
+ // generate a huge backlog of frames that we need to run through quickly.
+ next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
+ steady_clock::time_point now = steady_clock::now();
+ if (next_frame_start < now) {
+ pts_origin = frame->pts;
+ start = next_frame_start = now;
+ }
+ }
+ }
+ last_pts = frame->pts;
}
return true;
}
start = next_frame_start = steady_clock::now();
}
-bool FFmpegCapture::process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified)
+bool FFmpegCapture::process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified, bool *rewound)
{
// Process any queued commands from other threads.
vector<QueuedCommand> commands;
return true;
}
internal_rewind();
+ if (rewound != nullptr) {
+ *rewound = true;
+ }
break;
case QueuedCommand::CHANGE_RATE:
- start = next_frame_start;
+ // Change the origin to the last played frame.
+ start = compute_frame_start(last_pts, pts_origin, video_timebase, start, rate);
pts_origin = last_pts;
rate = cmd.new_rate;
break;
else
return AVFrameWithDeleter(nullptr);
}
+
+VideoFormat FFmpegCapture::construct_video_format(const AVFrame *frame, AVRational video_timebase)
+{
+ VideoFormat video_format;
+ video_format.width = width;
+ video_format.height = height;
+ if (pixel_format == bmusb::PixelFormat_8BitBGRA) {
+ video_format.stride = width * 4;
+ } else {
+ assert(pixel_format == bmusb::PixelFormat_8BitYCbCrPlanar);
+ video_format.stride = width;
+ }
+ video_format.frame_rate_nom = video_timebase.den;
+ video_format.frame_rate_den = av_frame_get_pkt_duration(frame) * video_timebase.num;
+ if (video_format.frame_rate_nom == 0 || video_format.frame_rate_den == 0) {
+ // Invalid frame rate.
+ video_format.frame_rate_nom = 60;
+ video_format.frame_rate_den = 1;
+ }
+ video_format.has_signal = true;
+ video_format.is_connected = true;
+ return video_format;
+}
+
+FrameAllocator::Frame FFmpegCapture::make_video_frame(const AVFrame *frame, const string &pathname, bool *error)
+{
+ *error = false;
+
+ FrameAllocator::Frame video_frame = video_frame_allocator->alloc_frame();
+ if (video_frame.data == nullptr) {
+ return video_frame;
+ }
+
+ if (sws_ctx == nullptr ||
+ sws_last_width != frame->width ||
+ sws_last_height != frame->height ||
+ sws_last_src_format != frame->format) {
+ sws_dst_format = decide_dst_format(AVPixelFormat(frame->format), pixel_format);
+ sws_ctx.reset(
+ sws_getContext(frame->width, frame->height, AVPixelFormat(frame->format),
+ width, height, sws_dst_format,
+ SWS_BICUBIC, nullptr, nullptr, nullptr));
+ sws_last_width = frame->width;
+ sws_last_height = frame->height;
+ sws_last_src_format = frame->format;
+ }
+ if (sws_ctx == nullptr) {
+ fprintf(stderr, "%s: Could not create scaler context\n", pathname.c_str());
+ *error = true;
+ return video_frame;
+ }
+
+ uint8_t *pic_data[4] = { nullptr, nullptr, nullptr, nullptr };
+ int linesizes[4] = { 0, 0, 0, 0 };
+ if (pixel_format == bmusb::PixelFormat_8BitBGRA) {
+ pic_data[0] = video_frame.data;
+ linesizes[0] = width * 4;
+ video_frame.len = (width * 4) * height;
+ } else {
+ assert(pixel_format == bmusb::PixelFormat_8BitYCbCrPlanar);
+ const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(sws_dst_format);
+
+ int chroma_width = AV_CEIL_RSHIFT(int(width), desc->log2_chroma_w);
+ int chroma_height = AV_CEIL_RSHIFT(int(height), desc->log2_chroma_h);
+
+ pic_data[0] = video_frame.data;
+ linesizes[0] = width;
+
+ pic_data[1] = pic_data[0] + width * height;
+ linesizes[1] = chroma_width;
+
+ pic_data[2] = pic_data[1] + chroma_width * chroma_height;
+ linesizes[2] = chroma_width;
+
+ video_frame.len = width * height + 2 * chroma_width * chroma_height;
+
+ current_frame_ycbcr_format = decode_ycbcr_format(desc, frame);
+ }
+ sws_scale(sws_ctx.get(), frame->data, frame->linesize, 0, frame->height, pic_data, linesizes);
+
+ return video_frame;
+}