+#include "x264_encoder.h"
+
+#include <stdio.h>
+#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#include <x264.h>
+#include <cstdint>
#include "defs.h"
#include "flags.h"
#include "mux.h"
#include "timebase.h"
-#include "x264_encoder.h"
+#include "x264_speed_control.h"
extern "C" {
+#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
}
using namespace std;
+namespace {
+
+void update_vbv_settings(x264_param_t *param)
+{
+ if (global_flags.x264_vbv_buffer_size < 0) {
+ param->rc.i_vbv_buffer_size = param->rc.i_bitrate; // One-second VBV.
+ } else {
+ param->rc.i_vbv_buffer_size = global_flags.x264_vbv_buffer_size;
+ }
+ if (global_flags.x264_vbv_max_bitrate < 0) {
+ param->rc.i_vbv_max_bitrate = param->rc.i_bitrate; // CBR.
+ } else {
+ param->rc.i_vbv_max_bitrate = global_flags.x264_vbv_max_bitrate;
+ }
+}
+
+} // namespace
+
X264Encoder::X264Encoder(AVOutputFormat *oformat)
: wants_global_headers(oformat->flags & AVFMT_GLOBALHEADER)
{
param.i_timebase_num = 1;
param.i_timebase_den = TIMEBASE;
param.i_keyint_max = 50; // About one second.
+ if (global_flags.x264_speedcontrol) {
+ param.i_frame_reference = 16; // Because speedcontrol is never allowed to change this above what we set at start.
+ }
// NOTE: These should be in sync with the ones in h264encode.cpp (sbs_rbsp()).
param.vui.i_vidformat = 5; // Unspecified.
param.rc.i_rc_method = X264_RC_ABR;
param.rc.i_bitrate = global_flags.x264_bitrate;
- if (global_flags.x264_vbv_buffer_size < 0) {
- param.rc.i_vbv_buffer_size = param.rc.i_bitrate; // One-second VBV.
- } else {
- param.rc.i_vbv_buffer_size = global_flags.x264_vbv_buffer_size;
- }
- if (global_flags.x264_vbv_max_bitrate < 0) {
- param.rc.i_vbv_max_bitrate = param.rc.i_bitrate; // CBR.
- } else {
- param.rc.i_vbv_max_bitrate = global_flags.x264_vbv_max_bitrate;
+ update_vbv_settings(¶m);
+ if (param.rc.i_vbv_max_bitrate > 0) {
+ // If the user wants VBV control to cap the max rate, it is
+ // also reasonable to assume that they are fine with the stream
+ // constantly being around that rate even for very low-complexity
+ // content; the obvious and extreme example being a static
+ // black picture.
+ //
+ // One would think it's fine to have low-complexity content use
+ // less bitrate, but it seems to cause problems in practice;
+ // e.g. VLC seems to often drop the stream (similar to a buffer
+ // underrun) in such cases, but only when streaming from Nageru,
+ // not when reading a dump of the same stream from disk.
+ // I'm not 100% sure whether it's in VLC (possibly some buffering
+ // in the HTTP layer), in microhttpd or somewhere in Nageru itself,
+ // but it's a typical case of problems that can arise. Similarly,
+ // TCP's congestion control is not always fond of the rate staying
+ // low for a while and then rising quickly -- a variation on the same
+ // problem.
+ //
+ // We solve this by simply asking x264 to fill in dummy bits
+ // in these cases, so that the bitrate stays reasonable constant.
+ // It's a waste of bandwidth, but it makes things go much more
+ // smoothly in these cases. (We don't do it if VBV control is off
+ // in general, not the least because it makes no sense and x264
+ // thus ignores the parameter.)
+ param.rc.b_filler = 1;
}
// Occasionally players have problem with extremely low quantizers;
// be on the safe side. Shouldn't affect quality in any meaningful way.
param.rc.i_qp_min = 5;
- // TODO: more flags here, via x264_param_parse().
+ for (const string &str : global_flags.x264_extra_param) {
+ const size_t pos = str.find(',');
+ if (pos == string::npos) {
+ if (x264_param_parse(¶m, str.c_str(), nullptr) != 0) {
+ fprintf(stderr, "ERROR: x264 rejected parameter '%s'\n", str.c_str());
+ }
+ } else {
+ const string key = str.substr(0, pos);
+ const string value = str.substr(pos + 1);
+ if (x264_param_parse(¶m, key.c_str(), value.c_str()) != 0) {
+ fprintf(stderr, "ERROR: x264 rejected parameter '%s' set to '%s'\n",
+ key.c_str(), value.c_str());
+ }
+ }
+ }
x264_param_apply_profile(¶m, "high");
exit(1);
}
+ if (global_flags.x264_speedcontrol) {
+ speed_control.reset(new X264SpeedControl(x264, /*f_speed=*/1.0f, X264_QUEUE_LENGTH, /*f_buffer_init=*/1.0f));
+ }
+
if (wants_global_headers) {
x264_nal_t *nal;
int num_nal;
void X264Encoder::encoder_thread_func()
{
- nice(5); // Note that x264 further nices some of its threads.
+ if (nice(5) == -1) { // Note that x264 further nices some of its threads.
+ perror("nice()");
+ // No exit; it's not fatal.
+ }
init_x264();
bool frames_left;
x264_nal_t *nal = nullptr;
int num_nal = 0;
x264_picture_t pic;
+ x264_picture_t *input_pic = nullptr;
if (qf.data) {
x264_picture_init(&pic);
pic.img.i_stride[1] = WIDTH / 2 * sizeof(uint16_t);
pic.opaque = reinterpret_cast<void *>(intptr_t(qf.duration));
- x264_encoder_encode(x264, &nal, &num_nal, &pic, &pic);
- } else {
- x264_encoder_encode(x264, &nal, &num_nal, nullptr, &pic);
+ input_pic = &pic;
+ }
+
+ // See if we have a new bitrate to change to.
+ unsigned new_rate = new_bitrate_kbit.exchange(0); // Read and clear.
+ if (new_rate != 0) {
+ if (speed_control) {
+ speed_control->set_config_override_function([new_rate](x264_param_t *param) {
+ param->rc.i_bitrate = new_rate;
+ update_vbv_settings(param);
+ });
+ } else {
+ x264_param_t param;
+ x264_encoder_parameters(x264, ¶m);
+ param.rc.i_bitrate = new_rate;
+ update_vbv_settings(¶m);
+ x264_encoder_reconfig(x264, ¶m);
+ }
+ }
+
+ if (speed_control) {
+ speed_control->before_frame(float(free_frames.size()) / X264_QUEUE_LENGTH, X264_QUEUE_LENGTH, 1e6 * qf.duration / TIMEBASE);
+ }
+ x264_encoder_encode(x264, &nal, &num_nal, input_pic, &pic);
+ if (speed_control) {
+ speed_control->after_frame();
}
// We really need one AVPacket for the entire frame, it seems,
projects / nageru / blobdiff