1 #include "ffmpeg_capture.h"
13 #include <libavcodec/avcodec.h>
14 #include <libavformat/avformat.h>
15 #include <libavutil/avutil.h>
16 #include <libavutil/error.h>
17 #include <libavutil/frame.h>
18 #include <libavutil/imgutils.h>
19 #include <libavutil/mem.h>
20 #include <libavutil/pixfmt.h>
21 #include <libavutil/opt.h>
22 #include <libswscale/swscale.h>
29 #include <unordered_set>
33 #include <movit/colorspace_conversion_effect.h>
35 #include "bmusb/bmusb.h"
36 #include "shared/ffmpeg_raii.h"
37 #include "ffmpeg_util.h"
39 #include "image_input.h"
40 #include "ref_counted_frame.h"
41 #include "shared/timebase.h"
48 using namespace std::chrono;
49 using namespace bmusb;
50 using namespace movit;
51 using namespace Eigen;
55 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)
57 const duration<double> pts((frame_pts - pts_origin) * double(video_timebase.num) / double(video_timebase.den));
58 return origin + duration_cast<steady_clock::duration>(pts / rate);
61 bool changed_since(const std::string &pathname, const timespec &ts)
67 if (stat(pathname.c_str(), &buf) != 0) {
68 fprintf(stderr, "%s: Couldn't check for new version, leaving the old in place.\n", pathname.c_str());
71 return (buf.st_mtim.tv_sec != ts.tv_sec || buf.st_mtim.tv_nsec != ts.tv_nsec);
74 bool is_full_range(const AVPixFmtDescriptor *desc)
76 // This is horrible, but there's no better way that I know of.
77 return (strchr(desc->name, 'j') != nullptr);
80 AVPixelFormat decide_dst_format(AVPixelFormat src_format, bmusb::PixelFormat dst_format_type)
82 if (dst_format_type == bmusb::PixelFormat_8BitBGRA) {
83 return AV_PIX_FMT_BGRA;
85 if (dst_format_type == FFmpegCapture::PixelFormat_NV12) {
86 return AV_PIX_FMT_NV12;
89 assert(dst_format_type == bmusb::PixelFormat_8BitYCbCrPlanar);
91 // If this is a non-Y'CbCr format, just convert to 4:4:4 Y'CbCr
92 // and be done with it. It's too strange to spend a lot of time on.
93 // (Let's hope there's no alpha.)
94 const AVPixFmtDescriptor *src_desc = av_pix_fmt_desc_get(src_format);
95 if (src_desc == nullptr ||
96 src_desc->nb_components != 3 ||
97 (src_desc->flags & AV_PIX_FMT_FLAG_RGB)) {
98 return AV_PIX_FMT_YUV444P;
101 // The best for us would be Cb and Cr together if possible,
102 // but FFmpeg doesn't support that except in the special case of
103 // NV12, so we need to go to planar even for the case of NV12.
104 // Thus, look for the closest (but no worse) 8-bit planar Y'CbCr format
105 // that matches in color range. (This will also include the case of
106 // the source format already being acceptable.)
107 bool src_full_range = is_full_range(src_desc);
108 const char *best_format = "yuv444p";
109 unsigned best_score = numeric_limits<unsigned>::max();
110 for (const AVPixFmtDescriptor *desc = av_pix_fmt_desc_next(nullptr);
112 desc = av_pix_fmt_desc_next(desc)) {
113 // Find planar Y'CbCr formats only.
114 if (desc->nb_components != 3) continue;
115 if (desc->flags & AV_PIX_FMT_FLAG_RGB) continue;
116 if (!(desc->flags & AV_PIX_FMT_FLAG_PLANAR)) continue;
117 if (desc->comp[0].plane != 0 ||
118 desc->comp[1].plane != 1 ||
119 desc->comp[2].plane != 2) continue;
121 // 8-bit formats only.
122 if (desc->flags & AV_PIX_FMT_FLAG_BE) continue;
123 if (desc->comp[0].depth != 8) continue;
125 // Same or better chroma resolution only.
126 int chroma_w_diff = src_desc->log2_chroma_w - desc->log2_chroma_w;
127 int chroma_h_diff = src_desc->log2_chroma_h - desc->log2_chroma_h;
128 if (chroma_w_diff < 0 || chroma_h_diff < 0)
131 // Matching full/limited range only.
132 if (is_full_range(desc) != src_full_range)
135 // Pick something with as little excess chroma resolution as possible.
136 unsigned score = (1 << (chroma_w_diff)) << chroma_h_diff;
137 if (score < best_score) {
139 best_format = desc->name;
142 return av_get_pix_fmt(best_format);
145 YCbCrFormat decode_ycbcr_format(const AVPixFmtDescriptor *desc, const AVFrame *frame, bool is_mjpeg, AVColorSpace *last_colorspace, AVChromaLocation *last_chroma_location)
148 AVColorSpace colorspace = frame->colorspace;
149 switch (colorspace) {
150 case AVCOL_SPC_BT709:
151 format.luma_coefficients = YCBCR_REC_709;
153 case AVCOL_SPC_BT470BG:
154 case AVCOL_SPC_SMPTE170M:
155 case AVCOL_SPC_SMPTE240M:
156 format.luma_coefficients = YCBCR_REC_601;
158 case AVCOL_SPC_BT2020_NCL:
159 format.luma_coefficients = YCBCR_REC_2020;
161 case AVCOL_SPC_UNSPECIFIED:
162 format.luma_coefficients = (frame->height >= 720 ? YCBCR_REC_709 : YCBCR_REC_601);
165 if (colorspace != *last_colorspace) {
166 fprintf(stderr, "Unknown Y'CbCr coefficient enum %d from FFmpeg; choosing Rec. 709.\n",
169 format.luma_coefficients = YCBCR_REC_709;
172 *last_colorspace = colorspace;
174 format.full_range = is_full_range(desc);
175 format.num_levels = 1 << desc->comp[0].depth;
176 format.chroma_subsampling_x = 1 << desc->log2_chroma_w;
177 format.chroma_subsampling_y = 1 << desc->log2_chroma_h;
179 switch (frame->chroma_location) {
180 case AVCHROMA_LOC_LEFT:
181 format.cb_x_position = 0.0;
182 format.cb_y_position = 0.5;
184 case AVCHROMA_LOC_CENTER:
185 format.cb_x_position = 0.5;
186 format.cb_y_position = 0.5;
188 case AVCHROMA_LOC_TOPLEFT:
189 format.cb_x_position = 0.0;
190 format.cb_y_position = 0.0;
192 case AVCHROMA_LOC_TOP:
193 format.cb_x_position = 0.5;
194 format.cb_y_position = 0.0;
196 case AVCHROMA_LOC_BOTTOMLEFT:
197 format.cb_x_position = 0.0;
198 format.cb_y_position = 1.0;
200 case AVCHROMA_LOC_BOTTOM:
201 format.cb_x_position = 0.5;
202 format.cb_y_position = 1.0;
205 if (frame->chroma_location != *last_chroma_location) {
206 fprintf(stderr, "Unknown chroma location coefficient enum %d from FFmpeg; choosing center.\n",
207 frame->chroma_location);
209 format.cb_x_position = 0.5;
210 format.cb_y_position = 0.5;
213 *last_chroma_location = frame->chroma_location;
215 if (is_mjpeg && !format.full_range) {
216 // Limited-range MJPEG is only detected by FFmpeg whenever a special
217 // JPEG comment is set, which means that in practice, the stream is
218 // almost certainly generated by Futatabi. Override FFmpeg's forced
219 // MJPEG defaults (it disregards the values set in the mux) with what
221 format.luma_coefficients = YCBCR_REC_709;
222 format.cb_x_position = 0.0;
223 format.cb_y_position = 0.5;
226 format.cr_x_position = format.cb_x_position;
227 format.cr_y_position = format.cb_y_position;
231 RGBTriplet get_neutral_color(AVDictionary *metadata)
233 if (metadata == nullptr) {
234 return RGBTriplet(1.0f, 1.0f, 1.0f);
236 AVDictionaryEntry *entry = av_dict_get(metadata, "WhitePoint", nullptr, 0);
237 if (entry == nullptr) {
238 return RGBTriplet(1.0f, 1.0f, 1.0f);
241 unsigned x_nom, x_den, y_nom, y_den;
242 if (sscanf(entry->value, " %u:%u , %u:%u", &x_nom, &x_den, &y_nom, &y_den) != 4) {
243 fprintf(stderr, "WARNING: Unable to parse white point '%s', using default white point\n", entry->value);
244 return RGBTriplet(1.0f, 1.0f, 1.0f);
247 double x = double(x_nom) / x_den;
248 double y = double(y_nom) / y_den;
249 double z = 1.0 - x - y;
251 Matrix3d rgb_to_xyz_matrix = movit::ColorspaceConversionEffect::get_xyz_matrix(COLORSPACE_sRGB);
252 Vector3d rgb = rgb_to_xyz_matrix.inverse() * Vector3d(x, y, z);
254 return RGBTriplet(rgb[0], rgb[1], rgb[2]);
259 FFmpegCapture::FFmpegCapture(const string &filename, unsigned width, unsigned height)
260 : filename(filename), width(width), height(height), video_timebase{1, 1}
262 description = "Video: " + filename;
264 last_frame = steady_clock::now();
266 avformat_network_init(); // In case someone wants this.
270 FFmpegCapture::FFmpegCapture(int srt_sock, const string &stream_id)
271 : srt_sock(srt_sock),
272 width(0), // Don't resize; SRT streams typically have stable resolution, and should behave much like regular cards in general.
274 pixel_format(bmusb::PixelFormat_8BitYCbCrPlanar),
277 if (stream_id.empty()) {
278 description = "SRT stream";
280 description = stream_id;
282 play_as_fast_as_possible = true;
284 last_frame = steady_clock::now();
288 FFmpegCapture::~FFmpegCapture()
290 if (has_dequeue_callbacks) {
291 dequeue_cleanup_callback();
293 swr_free(&resampler);
295 if (srt_sock != -1) {
301 void FFmpegCapture::configure_card()
303 if (video_frame_allocator == nullptr) {
304 owned_video_frame_allocator.reset(new MallocFrameAllocator(FRAME_SIZE, NUM_QUEUED_VIDEO_FRAMES));
305 set_video_frame_allocator(owned_video_frame_allocator.get());
307 if (audio_frame_allocator == nullptr) {
308 // Audio can come out in pretty large chunks, so increase from the default 1 MB.
309 owned_audio_frame_allocator.reset(new MallocFrameAllocator(1 << 20, NUM_QUEUED_AUDIO_FRAMES));
310 set_audio_frame_allocator(owned_audio_frame_allocator.get());
314 void FFmpegCapture::start_bm_capture()
320 producer_thread_should_quit.unquit();
321 producer_thread = thread(&FFmpegCapture::producer_thread_func, this);
324 void FFmpegCapture::stop_dequeue_thread()
330 producer_thread_should_quit.quit();
331 producer_thread.join();
334 std::map<uint32_t, VideoMode> FFmpegCapture::get_available_video_modes() const
336 // Note: This will never really be shown in the UI.
340 snprintf(buf, sizeof(buf), "%ux%u", sws_last_width, sws_last_height);
343 mode.autodetect = false;
344 mode.width = sws_last_width;
345 mode.height = sws_last_height;
346 mode.frame_rate_num = 60;
347 mode.frame_rate_den = 1;
348 mode.interlaced = false;
350 return {{ 0, mode }};
353 void FFmpegCapture::producer_thread_func()
355 char thread_name[16];
356 snprintf(thread_name, sizeof(thread_name), "FFmpeg_C_%d", card_index);
357 pthread_setname_np(pthread_self(), thread_name);
359 while (!producer_thread_should_quit.should_quit()) {
360 string filename_copy;
362 lock_guard<mutex> lock(filename_mu);
363 filename_copy = filename;
367 if (srt_sock == -1) {
368 pathname = search_for_file(filename_copy);
370 pathname = description;
372 if (pathname.empty()) {
373 send_disconnected_frame();
377 producer_thread_should_quit.sleep_for(seconds(1));
378 fprintf(stderr, "%s not found, sleeping one second and trying again...\n", filename_copy.c_str());
381 should_interrupt = false;
382 if (!play_video(pathname)) {
384 send_disconnected_frame();
388 fprintf(stderr, "Error when playing %s, sleeping one second and trying again...\n", pathname.c_str());
389 producer_thread_should_quit.sleep_for(seconds(1));
394 send_disconnected_frame();
398 // Probably just EOF, will exit the loop above on next test.
401 if (has_dequeue_callbacks) {
402 dequeue_cleanup_callback();
403 has_dequeue_callbacks = false;
407 void FFmpegCapture::send_disconnected_frame()
409 // Send an empty frame to signal that we have no signal anymore.
410 FrameAllocator::Frame video_frame = video_frame_allocator->alloc_frame();
411 size_t frame_width = width == 0 ? global_flags.width : width;
412 size_t frame_height = height == 0 ? global_flags.height : height;
413 if (video_frame.data) {
414 VideoFormat video_format;
415 video_format.width = frame_width;
416 video_format.height = frame_height;
417 video_format.frame_rate_nom = 60;
418 video_format.frame_rate_den = 1;
419 video_format.is_connected = false;
420 if (pixel_format == bmusb::PixelFormat_8BitBGRA) {
421 video_format.stride = frame_width * 4;
422 video_frame.len = frame_width * frame_height * 4;
423 memset(video_frame.data, 0, video_frame.len);
425 video_format.stride = frame_width;
426 current_frame_ycbcr_format.luma_coefficients = YCBCR_REC_709;
427 current_frame_ycbcr_format.full_range = true;
428 current_frame_ycbcr_format.num_levels = 256;
429 current_frame_ycbcr_format.chroma_subsampling_x = 2;
430 current_frame_ycbcr_format.chroma_subsampling_y = 2;
431 current_frame_ycbcr_format.cb_x_position = 0.0f;
432 current_frame_ycbcr_format.cb_y_position = 0.0f;
433 current_frame_ycbcr_format.cr_x_position = 0.0f;
434 current_frame_ycbcr_format.cr_y_position = 0.0f;
435 video_frame.len = frame_width * frame_height * 2;
436 memset(video_frame.data, 0, frame_width * frame_height);
437 memset(video_frame.data + frame_width * frame_height, 128, frame_width * frame_height); // Valid for both NV12 and planar.
440 if (frame_callback != nullptr) {
441 frame_callback(-1, AVRational{1, TIMEBASE}, -1, AVRational{1, TIMEBASE}, timecode++,
442 video_frame, /*video_offset=*/0, video_format,
443 FrameAllocator::Frame(), /*audio_offset=*/0, AudioFormat());
445 last_frame_was_connected = false;
450 if (card_disconnected_callback != nullptr) {
451 card_disconnected_callback();
456 template<AVHWDeviceType type>
457 AVPixelFormat get_hw_format(AVCodecContext *ctx, const AVPixelFormat *fmt)
459 bool found_config_of_right_type = false;
460 for (int i = 0;; ++i) { // Termination condition inside loop.
461 const AVCodecHWConfig *config = avcodec_get_hw_config(ctx->codec, i);
462 if (config == nullptr) { // End of list.
465 if (!(config->methods & AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX) ||
466 config->device_type != type) {
467 // Not interesting for us.
471 // We have a config of the right type, but does it actually support
472 // the pixel format we want? (Seemingly, FFmpeg's way of signaling errors
473 // is to just replace the pixel format with a software-decoded one,
475 found_config_of_right_type = true;
476 for (const AVPixelFormat *fmt_ptr = fmt; *fmt_ptr != -1; ++fmt_ptr) {
477 if (config->pix_fmt == *fmt_ptr) {
478 fprintf(stderr, "Initialized '%s' hardware decoding for codec '%s'.\n",
479 av_hwdevice_get_type_name(type), ctx->codec->name);
480 if (ctx->profile == FF_PROFILE_H264_BASELINE) {
481 fprintf(stderr, "WARNING: Stream claims to be H.264 Baseline, which is generally poorly supported in hardware decoders.\n");
482 fprintf(stderr, " Consider encoding it as Constrained Baseline, Main or High instead.\n");
483 fprintf(stderr, " Decoding might fail and fall back to software.\n");
485 return config->pix_fmt;
488 fprintf(stderr, "Decoder '%s' supports only these pixel formats:", ctx->codec->name);
489 unordered_set<AVPixelFormat> seen;
490 for (const AVPixelFormat *fmt_ptr = fmt; *fmt_ptr != -1; ++fmt_ptr) {
491 if (!seen.count(*fmt_ptr)) {
492 fprintf(stderr, " %s", av_get_pix_fmt_name(*fmt_ptr));
493 seen.insert(*fmt_ptr);
496 fprintf(stderr, " (wanted %s for hardware acceleration)\n", av_get_pix_fmt_name(config->pix_fmt));
500 if (!found_config_of_right_type) {
501 fprintf(stderr, "Decoder '%s' does not support device type '%s'.\n", ctx->codec->name, av_hwdevice_get_type_name(type));
504 // We found no VA-API formats, so take the first software format.
505 for (const AVPixelFormat *fmt_ptr = fmt; *fmt_ptr != -1; ++fmt_ptr) {
506 if ((av_pix_fmt_desc_get(*fmt_ptr)->flags & AV_PIX_FMT_FLAG_HWACCEL) == 0) {
507 fprintf(stderr, "Falling back to software format %s.\n", av_get_pix_fmt_name(*fmt_ptr));
512 // Fallback: Just return anything. (Should never really happen.)
516 bool FFmpegCapture::play_video(const string &pathname)
518 // Note: Call before open, not after; otherwise, there's a race.
519 // (There is now, too, but it tips the correct way. We could use fstat()
520 // if we had the file descriptor.)
521 timespec last_modified;
523 if (stat(pathname.c_str(), &buf) != 0) {
524 // Probably some sort of protocol, so can't stat.
525 last_modified.tv_sec = -1;
527 last_modified = buf.st_mtim;
529 last_colorspace = static_cast<AVColorSpace>(-1);
530 last_chroma_location = static_cast<AVChromaLocation>(-1);
532 AVFormatContextWithCloser format_ctx;
533 if (srt_sock == -1) {
534 // Regular file (or stream).
535 frame_timeout_started = steady_clock::now();
536 frame_timeout_valid = true;
537 format_ctx = avformat_open_input_unique(pathname.c_str(), /*fmt=*/nullptr,
539 AVIOInterruptCB{ &FFmpegCapture::interrupt_cb_thunk, this });
540 frame_timeout_valid = false;
543 // SRT socket, already opened.
544 const AVInputFormat *mpegts_fmt = av_find_input_format("mpegts");
545 format_ctx = avformat_open_input_unique(&FFmpegCapture::read_srt_thunk, this,
546 mpegts_fmt, /*options=*/nullptr,
547 AVIOInterruptCB{ &FFmpegCapture::interrupt_cb_thunk, this });
552 if (format_ctx == nullptr) {
553 fprintf(stderr, "%s: Error opening file\n", pathname.c_str());
557 if (avformat_find_stream_info(format_ctx.get(), nullptr) < 0) {
558 fprintf(stderr, "%s: Error finding stream info\n", pathname.c_str());
562 int video_stream_index = find_stream_index(format_ctx.get(), AVMEDIA_TYPE_VIDEO);
563 if (video_stream_index == -1) {
564 fprintf(stderr, "%s: No video stream found\n", pathname.c_str());
568 int audio_stream_index = find_stream_index(format_ctx.get(), AVMEDIA_TYPE_AUDIO);
569 int subtitle_stream_index = find_stream_index(format_ctx.get(), AVMEDIA_TYPE_SUBTITLE);
570 has_last_subtitle = false;
572 // Open video decoder.
573 const AVCodecParameters *video_codecpar = format_ctx->streams[video_stream_index]->codecpar;
574 const AVCodec *video_codec = avcodec_find_decoder(video_codecpar->codec_id);
576 video_timebase = format_ctx->streams[video_stream_index]->time_base;
577 AVCodecContextWithDeleter video_codec_ctx = avcodec_alloc_context3_unique(nullptr);
578 if (avcodec_parameters_to_context(video_codec_ctx.get(), video_codecpar) < 0) {
579 fprintf(stderr, "%s: Cannot fill video codec parameters\n", pathname.c_str());
582 if (video_codec == nullptr) {
583 fprintf(stderr, "%s: Cannot find video decoder\n", pathname.c_str());
587 // Seemingly, it's not too easy to make something that just initializes
588 // “whatever goes”, so we don't get CUDA or VULKAN or whatever here
589 // without enumerating through several different types.
590 // VA-API and VDPAU will do for now. We prioritize VDPAU for the
591 // simple reason that there's a VA-API-via-VDPAU emulation for NVidia
592 // cards that seems to work, but just hangs when trying to transfer the frame.
594 // Note that we don't actually check codec support beforehand,
595 // so if you have a low-end VDPAU device but a high-end VA-API device,
596 // you lose out on the extra codec support from the latter.
597 AVBufferRef *hw_device_ctx = nullptr;
598 if (av_hwdevice_ctx_create(&hw_device_ctx, AV_HWDEVICE_TYPE_VDPAU, nullptr, nullptr, 0) >= 0) {
599 video_codec_ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx);
600 video_codec_ctx->get_format = get_hw_format<AV_HWDEVICE_TYPE_VDPAU>;
601 } else if (av_hwdevice_ctx_create(&hw_device_ctx, AV_HWDEVICE_TYPE_VAAPI, nullptr, nullptr, 0) >= 0) {
602 video_codec_ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx);
603 video_codec_ctx->get_format = get_hw_format<AV_HWDEVICE_TYPE_VAAPI>;
605 fprintf(stderr, "Failed to initialize VA-API or VDPAU for FFmpeg acceleration. Decoding video in software.\n");
608 if (avcodec_open2(video_codec_ctx.get(), video_codec, nullptr) < 0) {
609 fprintf(stderr, "%s: Cannot open video decoder\n", pathname.c_str());
612 unique_ptr<AVCodecContext, decltype(avcodec_close)*> video_codec_ctx_cleanup(
613 video_codec_ctx.get(), avcodec_close);
615 // Used in decode_ycbcr_format().
616 is_mjpeg = video_codecpar->codec_id == AV_CODEC_ID_MJPEG;
618 // Open audio decoder, if we have audio.
619 AVCodecContextWithDeleter audio_codec_ctx;
620 if (audio_stream_index != -1) {
621 audio_codec_ctx = avcodec_alloc_context3_unique(nullptr);
622 const AVCodecParameters *audio_codecpar = format_ctx->streams[audio_stream_index]->codecpar;
623 audio_timebase = format_ctx->streams[audio_stream_index]->time_base;
624 if (avcodec_parameters_to_context(audio_codec_ctx.get(), audio_codecpar) < 0) {
625 fprintf(stderr, "%s: Cannot fill audio codec parameters\n", pathname.c_str());
628 const AVCodec *audio_codec = avcodec_find_decoder(audio_codecpar->codec_id);
629 if (audio_codec == nullptr) {
630 fprintf(stderr, "%s: Cannot find audio decoder\n", pathname.c_str());
633 if (avcodec_open2(audio_codec_ctx.get(), audio_codec, nullptr) < 0) {
634 fprintf(stderr, "%s: Cannot open audio decoder\n", pathname.c_str());
638 unique_ptr<AVCodecContext, decltype(avcodec_close)*> audio_codec_ctx_cleanup(
639 audio_codec_ctx.get(), avcodec_close);
644 bool first_frame = true;
645 int consecutive_errors = 0;
646 while (!producer_thread_should_quit.should_quit()) {
647 if (process_queued_commands(format_ctx.get(), pathname, last_modified, /*rewound=*/nullptr)) {
650 if (should_interrupt.load()) {
651 // Check as a failsafe, so that we don't need to rely on avio if we don't have to.
654 UniqueFrame audio_frame = audio_frame_allocator->alloc_frame();
655 AudioFormat audio_format;
659 frame_timeout_started = steady_clock::now();
660 frame_timeout_valid = true;
661 AVFrameWithDeleter frame = decode_frame(format_ctx.get(), video_codec_ctx.get(), audio_codec_ctx.get(),
662 pathname, video_stream_index, audio_stream_index, subtitle_stream_index, audio_frame.get(), &audio_format, &audio_pts, &error);
663 frame_timeout_valid = false;
664 if (should_interrupt.load()) {
665 // Abort no matter whether we got a frame or not.
669 if (++consecutive_errors >= 100) {
670 fprintf(stderr, "More than 100 consecutive error video frames, aborting playback.\n");
676 consecutive_errors = 0;
678 if (frame == nullptr) {
679 // EOF. Loop back to the start if we can.
680 if (format_ctx->pb != nullptr && format_ctx->pb->seekable == 0) {
681 // Not seekable (but seemingly, sometimes av_seek_frame() would return 0 anyway,
685 if (av_seek_frame(format_ctx.get(), /*stream_index=*/-1, /*timestamp=*/0, /*flags=*/0) < 0) {
686 fprintf(stderr, "%s: Rewind failed, not looping.\n", pathname.c_str());
689 if (video_codec_ctx != nullptr) {
690 avcodec_flush_buffers(video_codec_ctx.get());
692 if (audio_codec_ctx != nullptr) {
693 avcodec_flush_buffers(audio_codec_ctx.get());
695 // If the file has changed since last time, return to get it reloaded.
696 // Note that depending on how you move the file into place, you might
697 // end up corrupting the one you're already playing, so this path
698 // might not trigger.
699 if (changed_since(pathname, last_modified)) {
706 VideoFormat video_format = construct_video_format(frame.get(), video_timebase);
707 if (video_format.frame_rate_nom == 0 || video_format.frame_rate_den == 0) {
708 // Invalid frame rate; try constructing it from the previous frame length.
709 // (This is especially important if we are the master card, for SRT,
710 // since it affects audio. Not all senders have good timebases
711 // (e.g., Larix rounds first to timebase 1000 and then multiplies by
712 // 90 from there, it seems), but it's much better to have an oscillating
713 // value than just locking at 60.
714 if (last_pts != 0 && frame->pts > last_pts) {
715 int64_t pts_diff = frame->pts - last_pts;
716 video_format.frame_rate_nom = video_timebase.den;
717 video_format.frame_rate_den = video_timebase.num * pts_diff;
719 video_format.frame_rate_nom = 60;
720 video_format.frame_rate_den = 1;
723 UniqueFrame video_frame = make_video_frame(frame.get(), pathname, &error);
729 if (last_pts == 0 && pts_origin == 0) {
730 pts_origin = frame->pts;
732 steady_clock::time_point now = steady_clock::now();
733 if (play_as_fast_as_possible) {
734 video_frame->received_timestamp = now;
735 audio_frame->received_timestamp = now;
736 next_frame_start = now;
738 next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
739 if (first_frame && last_frame_was_connected) {
740 // If reconnect took more than one second, this is probably a live feed,
741 // and we should reset the resampler. (Or the rate is really, really low,
742 // in which case a reset on the first frame is fine anyway.)
743 if (duration<double>(next_frame_start - last_frame).count() >= 1.0) {
744 last_frame_was_connected = false;
747 video_frame->received_timestamp = next_frame_start;
749 // The easiest way to get all the rate conversions etc. right is to move the
750 // audio PTS into the video PTS timebase and go from there. (We'll get some
751 // rounding issues, but they should not be a big problem.)
752 int64_t audio_pts_as_video_pts = av_rescale_q(audio_pts, audio_timebase, video_timebase);
753 audio_frame->received_timestamp = compute_frame_start(audio_pts_as_video_pts, pts_origin, video_timebase, start, rate);
755 if (audio_frame->len != 0) {
756 // The received timestamps in Nageru are measured after we've just received the frame.
757 // However, pts (especially audio pts) is at the _beginning_ of the frame.
758 // If we have locked audio, the distinction doesn't really matter, as pts is
759 // on a relative scale and a fixed offset is fine. But if we don't, we will have
760 // a different number of samples each time, which will cause huge audio jitter
761 // and throw off the resampler.
763 // In a sense, we should have compensated by adding the frame and audio lengths
764 // to video_frame->received_timestamp and audio_frame->received_timestamp respectively,
765 // but that would mean extra waiting in sleep_until(). All we need is that they
766 // are correct relative to each other, though (and to the other frames we send),
767 // so just align the end of the audio frame, and we're fine.
768 size_t num_samples = (audio_frame->len * 8) / audio_format.bits_per_sample / audio_format.num_channels;
769 double offset = double(num_samples) / OUTPUT_FREQUENCY -
770 double(video_format.frame_rate_den) / video_format.frame_rate_nom;
771 audio_frame->received_timestamp += duration_cast<steady_clock::duration>(duration<double>(offset));
774 if (duration<double>(now - next_frame_start).count() >= 0.1) {
775 // If we don't have enough CPU to keep up, or if we have a live stream
776 // where the initial origin was somehow wrong, we could be behind indefinitely.
777 // In particular, this will give the audio resampler problems as it tries
778 // to speed up to reduce the delay, hitting the low end of the buffer every time.
779 fprintf(stderr, "%s: Playback %.0f ms behind, resetting time scale\n",
781 1e3 * duration<double>(now - next_frame_start).count());
782 pts_origin = frame->pts;
783 start = next_frame_start = now;
784 timecode += TYPICAL_FPS * 2 + 1;
787 bool finished_wakeup;
788 if (play_as_fast_as_possible) {
789 finished_wakeup = !producer_thread_should_quit.should_quit();
791 finished_wakeup = producer_thread_should_quit.sleep_until(next_frame_start);
793 if (finished_wakeup) {
794 if (audio_frame->len > 0) {
795 assert(audio_pts != -1);
797 if (!last_frame_was_connected) {
798 // We're recovering from an error (or really slow load, see above).
799 // Make sure to get the audio resampler reset. (This is a hack;
800 // ideally, the frame callback should just accept a way to signal
801 // audio discontinuity.)
802 timecode += TYPICAL_FPS * 2 + 1;
804 last_neutral_color = get_neutral_color(frame->metadata);
805 if (frame_callback != nullptr) {
806 frame_callback(frame->pts, video_timebase, audio_pts, audio_timebase, timecode++,
807 video_frame.get_and_release(), 0, video_format,
808 audio_frame.get_and_release(), 0, audio_format);
811 last_frame = steady_clock::now();
812 last_frame_was_connected = true;
815 if (producer_thread_should_quit.should_quit()) break;
817 bool rewound = false;
818 if (process_queued_commands(format_ctx.get(), pathname, last_modified, &rewound)) {
821 // If we just rewound, drop this frame on the floor and be done.
825 // OK, we didn't, so probably a rate change. Recalculate next_frame_start,
826 // but if it's now in the past, we'll reset the origin, so that we don't
827 // generate a huge backlog of frames that we need to run through quickly.
828 next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
829 steady_clock::time_point now = steady_clock::now();
830 if (next_frame_start < now) {
831 pts_origin = frame->pts;
832 start = next_frame_start = now;
836 last_pts = frame->pts;
841 void FFmpegCapture::internal_rewind()
843 pts_origin = last_pts = 0;
844 start = next_frame_start = steady_clock::now();
847 bool FFmpegCapture::process_queued_commands(AVFormatContext *format_ctx, const std::string &pathname, timespec last_modified, bool *rewound)
849 // Process any queued commands from other threads.
850 vector<QueuedCommand> commands;
852 lock_guard<mutex> lock(queue_mu);
853 swap(commands, command_queue);
855 for (const QueuedCommand &cmd : commands) {
856 switch (cmd.command) {
857 case QueuedCommand::REWIND:
858 if (av_seek_frame(format_ctx, /*stream_index=*/-1, /*timestamp=*/0, /*flags=*/0) < 0) {
859 fprintf(stderr, "%s: Rewind failed, stopping play.\n", pathname.c_str());
861 // If the file has changed since last time, return to get it reloaded.
862 // Note that depending on how you move the file into place, you might
863 // end up corrupting the one you're already playing, so this path
864 // might not trigger.
865 if (changed_since(pathname, last_modified)) {
869 if (rewound != nullptr) {
874 case QueuedCommand::CHANGE_RATE:
875 // Change the origin to the last played frame.
876 start = compute_frame_start(last_pts, pts_origin, video_timebase, start, rate);
877 pts_origin = last_pts;
879 play_as_fast_as_possible = (rate >= 10.0);
890 AVFrameWithDeleter FFmpegCapture::decode_frame(AVFormatContext *format_ctx, AVCodecContext *video_codec_ctx, AVCodecContext *audio_codec_ctx,
891 const std::string &pathname, int video_stream_index, int audio_stream_index, int subtitle_stream_index,
892 FrameAllocator::Frame *audio_frame, AudioFormat *audio_format, int64_t *audio_pts, bool *error)
896 // Read packets until we have a frame or there are none left.
897 bool frame_finished = false;
898 AVFrameWithDeleter audio_avframe = av_frame_alloc_unique();
899 AVFrameWithDeleter video_avframe = av_frame_alloc_unique();
902 bool has_audio = false;
905 unique_ptr<AVPacket, decltype(av_packet_unref)*> pkt_cleanup(
906 &pkt, av_packet_unref);
907 av_init_packet(&pkt);
910 if (av_read_frame(format_ctx, &pkt) == 0) {
911 if (pkt.stream_index == audio_stream_index && audio_callback != nullptr) {
912 audio_callback(&pkt, format_ctx->streams[audio_stream_index]->time_base);
914 if (pkt.stream_index == video_stream_index && video_callback != nullptr) {
915 video_callback(&pkt, format_ctx->streams[video_stream_index]->time_base);
917 if (pkt.stream_index == video_stream_index && global_flags.transcode_video) {
918 if (avcodec_send_packet(video_codec_ctx, &pkt) < 0) {
919 fprintf(stderr, "%s: Cannot send packet to video codec.\n", pathname.c_str());
921 return AVFrameWithDeleter(nullptr);
923 } else if (pkt.stream_index == audio_stream_index && global_flags.transcode_audio) {
925 if (avcodec_send_packet(audio_codec_ctx, &pkt) < 0) {
926 fprintf(stderr, "%s: Cannot send packet to audio codec.\n", pathname.c_str());
928 return AVFrameWithDeleter(nullptr);
930 } else if (pkt.stream_index == subtitle_stream_index) {
931 last_subtitle = string(reinterpret_cast<const char *>(pkt.data), pkt.size);
932 has_last_subtitle = true;
935 eof = true; // Or error, but ignore that for the time being.
938 // Decode audio, if any.
941 int err = avcodec_receive_frame(audio_codec_ctx, audio_avframe.get());
943 if (*audio_pts == -1) {
944 *audio_pts = audio_avframe->pts;
946 convert_audio(audio_avframe.get(), audio_frame, audio_format);
947 } else if (err == AVERROR(EAGAIN)) {
950 fprintf(stderr, "%s: Cannot receive frame from audio codec.\n", pathname.c_str());
952 return AVFrameWithDeleter(nullptr);
957 // Decode video, if we have a frame.
958 int err = avcodec_receive_frame(video_codec_ctx, video_avframe.get());
960 if (video_avframe->format == AV_PIX_FMT_VAAPI ||
961 video_avframe->format == AV_PIX_FMT_VDPAU) {
962 // Get the frame down to the CPU. (TODO: See if we can keep it
963 // on the GPU all the way, since it will be going up again later.
964 // However, this only works if the OpenGL GPU is the same one.)
965 AVFrameWithDeleter sw_frame = av_frame_alloc_unique();
966 int err = av_hwframe_transfer_data(sw_frame.get(), video_avframe.get(), 0);
968 fprintf(stderr, "%s: Cannot transfer hardware video frame to software.\n", pathname.c_str());
970 return AVFrameWithDeleter(nullptr);
972 sw_frame->pts = video_avframe->pts;
973 sw_frame->pkt_duration = video_avframe->pkt_duration;
974 video_avframe = move(sw_frame);
976 frame_finished = true;
978 } else if (err != AVERROR(EAGAIN)) {
979 fprintf(stderr, "%s: Cannot receive frame from video codec.\n", pathname.c_str());
981 return AVFrameWithDeleter(nullptr);
986 return video_avframe;
988 return AVFrameWithDeleter(nullptr);
991 void FFmpegCapture::convert_audio(const AVFrame *audio_avframe, FrameAllocator::Frame *audio_frame, AudioFormat *audio_format)
993 // Decide on a format. If there already is one in this audio frame,
994 // we're pretty much forced to use it. If not, we try to find an exact match.
995 // If that still doesn't work, we default to 32-bit signed chunked
996 // (float would be nice, but there's really no way to signal that yet).
997 AVSampleFormat dst_format;
998 if (audio_format->bits_per_sample == 0) {
999 switch (audio_avframe->format) {
1000 case AV_SAMPLE_FMT_S16:
1001 case AV_SAMPLE_FMT_S16P:
1002 audio_format->bits_per_sample = 16;
1003 dst_format = AV_SAMPLE_FMT_S16;
1005 case AV_SAMPLE_FMT_S32:
1006 case AV_SAMPLE_FMT_S32P:
1008 audio_format->bits_per_sample = 32;
1009 dst_format = AV_SAMPLE_FMT_S32;
1012 } else if (audio_format->bits_per_sample == 16) {
1013 dst_format = AV_SAMPLE_FMT_S16;
1014 } else if (audio_format->bits_per_sample == 32) {
1015 dst_format = AV_SAMPLE_FMT_S32;
1019 audio_format->num_channels = 2;
1021 int64_t channel_layout = audio_avframe->channel_layout;
1022 if (channel_layout == 0) {
1023 channel_layout = av_get_default_channel_layout(audio_avframe->channels);
1026 if (resampler == nullptr ||
1027 audio_avframe->format != last_src_format ||
1028 dst_format != last_dst_format ||
1029 channel_layout != last_channel_layout ||
1030 audio_avframe->sample_rate != last_sample_rate) {
1031 swr_free(&resampler);
1032 resampler = swr_alloc_set_opts(nullptr,
1033 /*out_ch_layout=*/AV_CH_LAYOUT_STEREO_DOWNMIX,
1034 /*out_sample_fmt=*/dst_format,
1035 /*out_sample_rate=*/OUTPUT_FREQUENCY,
1036 /*in_ch_layout=*/channel_layout,
1037 /*in_sample_fmt=*/AVSampleFormat(audio_avframe->format),
1038 /*in_sample_rate=*/audio_avframe->sample_rate,
1040 /*log_ctx=*/nullptr);
1042 if (resampler == nullptr) {
1043 fprintf(stderr, "Allocating resampler failed.\n");
1047 if (swr_init(resampler) < 0) {
1048 fprintf(stderr, "Could not open resample context.\n");
1052 last_src_format = AVSampleFormat(audio_avframe->format);
1053 last_dst_format = dst_format;
1054 last_channel_layout = channel_layout;
1055 last_sample_rate = audio_avframe->sample_rate;
1058 size_t bytes_per_sample = (audio_format->bits_per_sample / 8) * 2;
1059 size_t num_samples_room = (audio_frame->size - audio_frame->len) / bytes_per_sample;
1061 uint8_t *data = audio_frame->data + audio_frame->len;
1062 int out_samples = swr_convert(resampler, &data, num_samples_room,
1063 const_cast<const uint8_t **>(audio_avframe->data), audio_avframe->nb_samples);
1064 if (out_samples < 0) {
1065 fprintf(stderr, "Audio conversion failed.\n");
1069 audio_frame->len += out_samples * bytes_per_sample;
1072 VideoFormat FFmpegCapture::construct_video_format(const AVFrame *frame, AVRational video_timebase)
1074 VideoFormat video_format;
1075 video_format.width = frame_width(frame);
1076 video_format.height = frame_height(frame);
1077 if (pixel_format == bmusb::PixelFormat_8BitBGRA) {
1078 video_format.stride = frame_width(frame) * 4;
1079 } else if (pixel_format == FFmpegCapture::PixelFormat_NV12) {
1080 video_format.stride = frame_width(frame);
1082 assert(pixel_format == bmusb::PixelFormat_8BitYCbCrPlanar);
1083 video_format.stride = frame_width(frame);
1085 video_format.frame_rate_nom = video_timebase.den;
1086 video_format.frame_rate_den = frame->pkt_duration * video_timebase.num;
1087 video_format.has_signal = true;
1088 video_format.is_connected = true;
1089 return video_format;
1092 UniqueFrame FFmpegCapture::make_video_frame(const AVFrame *frame, const string &pathname, bool *error)
1096 UniqueFrame video_frame(video_frame_allocator->alloc_frame());
1097 if (video_frame->data == nullptr) {
1101 if (sws_ctx == nullptr ||
1102 sws_last_width != frame->width ||
1103 sws_last_height != frame->height ||
1104 sws_last_src_format != frame->format) {
1105 sws_dst_format = decide_dst_format(AVPixelFormat(frame->format), pixel_format);
1107 sws_getContext(frame->width, frame->height, AVPixelFormat(frame->format),
1108 frame_width(frame), frame_height(frame), sws_dst_format,
1109 SWS_BICUBIC, nullptr, nullptr, nullptr));
1110 sws_last_width = frame->width;
1111 sws_last_height = frame->height;
1112 sws_last_src_format = frame->format;
1114 if (sws_ctx == nullptr) {
1115 fprintf(stderr, "%s: Could not create scaler context\n", pathname.c_str());
1120 uint8_t *pic_data[4] = { nullptr, nullptr, nullptr, nullptr };
1121 int linesizes[4] = { 0, 0, 0, 0 };
1122 if (pixel_format == bmusb::PixelFormat_8BitBGRA) {
1123 pic_data[0] = video_frame->data;
1124 linesizes[0] = frame_width(frame) * 4;
1125 video_frame->len = (frame_width(frame) * 4) * frame_height(frame);
1126 } else if (pixel_format == PixelFormat_NV12) {
1127 pic_data[0] = video_frame->data;
1128 linesizes[0] = frame_width(frame);
1130 pic_data[1] = pic_data[0] + frame_width(frame) * frame_height(frame);
1131 linesizes[1] = frame_width(frame);
1133 video_frame->len = (frame_width(frame) * 2) * frame_height(frame);
1135 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(sws_dst_format);
1136 current_frame_ycbcr_format = decode_ycbcr_format(desc, frame, is_mjpeg, &last_colorspace, &last_chroma_location);
1138 assert(pixel_format == bmusb::PixelFormat_8BitYCbCrPlanar);
1139 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(sws_dst_format);
1141 int chroma_width = AV_CEIL_RSHIFT(int(frame_width(frame)), desc->log2_chroma_w);
1142 int chroma_height = AV_CEIL_RSHIFT(int(frame_height(frame)), desc->log2_chroma_h);
1144 pic_data[0] = video_frame->data;
1145 linesizes[0] = frame_width(frame);
1147 pic_data[1] = pic_data[0] + frame_width(frame) * frame_height(frame);
1148 linesizes[1] = chroma_width;
1150 pic_data[2] = pic_data[1] + chroma_width * chroma_height;
1151 linesizes[2] = chroma_width;
1153 video_frame->len = frame_width(frame) * frame_height(frame) + 2 * chroma_width * chroma_height;
1155 current_frame_ycbcr_format = decode_ycbcr_format(desc, frame, is_mjpeg, &last_colorspace, &last_chroma_location);
1158 // FIXME: Currently, if the video is too high-res for one of the allocated
1159 // frames, we simply refuse to scale it here to avoid crashes. It would be better
1160 // if we could somehow signal getting larger frames, especially as 4K is a thing now.
1161 if (video_frame->len > FRAME_SIZE) {
1162 fprintf(stderr, "%s: Decoded frame would be larger than supported FRAME_SIZE (%zu > %u), not decoding.\n", pathname.c_str(), video_frame->len, FRAME_SIZE);
1167 sws_scale(sws_ctx.get(), frame->data, frame->linesize, 0, frame->height, pic_data, linesizes);
1172 int FFmpegCapture::interrupt_cb_thunk(void *opaque)
1174 return reinterpret_cast<FFmpegCapture *>(opaque)->interrupt_cb();
1177 int FFmpegCapture::interrupt_cb()
1179 // If ten seconds is gone without anything happening, we assume that
1180 // we are in a network stream that died and FFmpeg just didn't
1181 // pick it up (or perhaps it just hung, keeping the connection open).
1182 // Called back approximately every 100 ms if something is hanging,
1183 // so we get more than enough accuracy for our purposes.
1184 if (!should_interrupt && frame_timeout_valid &&
1185 duration<double>(steady_clock::now() - frame_timeout_started).count() >= 10.0) {
1186 string filename_copy;
1188 lock_guard<mutex> lock(filename_mu);
1189 filename_copy = filename;
1191 fprintf(stderr, "%s: No frame for more than 10 seconds, restarting stream.\n", filename.c_str());
1192 should_interrupt = true;
1194 return should_interrupt.load();
1197 unsigned FFmpegCapture::frame_width(const AVFrame *frame) const
1200 return frame->width;
1206 unsigned FFmpegCapture::frame_height(const AVFrame *frame) const
1209 return frame->height;
1216 int FFmpegCapture::read_srt_thunk(void *opaque, uint8_t *buf, int buf_size)
1218 return reinterpret_cast<FFmpegCapture *>(opaque)->read_srt(buf, buf_size);
1221 int FFmpegCapture::read_srt(uint8_t *buf, int buf_size)
1223 SRT_MSGCTRL mc = srt_msgctrl_default;
1224 return srt_recvmsg2(srt_sock, reinterpret_cast<char *>(buf), buf_size, &mc);