Support CRF for x264, similar to the CQP mode we already use in Quick Sync Video.

diff --git a/flags.cpp b/flags.cpp
index ee575c57863984621386dcbcee11781857afa222..acd054181c2403de736d7b0fe1cbef8d734761be 100644 (file)
--- a/flags.cpp
+++ b/flags.cpp
@@ -25,6 +25,7 @@ enum LongOption {
        OPTION_X264_SPEEDCONTROL,
        OPTION_X264_SPEEDCONTROL_VERBOSE,
        OPTION_X264_BITRATE,
+       OPTION_X264_CRF,
        OPTION_X264_VBV_BUFSIZE,
        OPTION_X264_VBV_MAX_BITRATE,
        OPTION_X264_PARAM,
@@ -86,6 +87,7 @@ void usage()
        fprintf(stderr, "      --x264-speedcontrol-verbose  output speedcontrol debugging statistics\n");
        fprintf(stderr, "      --x264-bitrate              x264 bitrate (in kilobit/sec, default %d)\n",
                DEFAULT_X264_OUTPUT_BIT_RATE);
+       fprintf(stderr, "      --x264-crf=VALUE            quality-based VBR (-12 to 51), incompatible with --x264-bitrate and VBV\n");
        fprintf(stderr, "      --x264-vbv-bufsize          x264 VBV size (in kilobits, 0 = one-frame VBV,\n");
        fprintf(stderr, "                                  default: same as --x264-bitrate, that is, one-second VBV)\n");
        fprintf(stderr, "      --x264-vbv-max-bitrate      x264 local max bitrate (in kilobit/sec per --vbv-bufsize,\n");
@@ -157,6 +159,7 @@ void parse_flags(int argc, char * const argv[])
                { "x264-speedcontrol", no_argument, 0, OPTION_X264_SPEEDCONTROL },
                { "x264-speedcontrol-verbose", no_argument, 0, OPTION_X264_SPEEDCONTROL_VERBOSE },
                { "x264-bitrate", required_argument, 0, OPTION_X264_BITRATE },
+               { "x264-crf", required_argument, 0, OPTION_X264_CRF },
                { "x264-vbv-bufsize", required_argument, 0, OPTION_X264_VBV_BUFSIZE },
                { "x264-vbv-max-bitrate", required_argument, 0, OPTION_X264_VBV_MAX_BITRATE },
                { "x264-param", required_argument, 0, OPTION_X264_PARAM },
@@ -288,6 +291,9 @@ void parse_flags(int argc, char * const argv[])
                case OPTION_X264_BITRATE:
                        global_flags.x264_bitrate = atoi(optarg);
                        break;
+               case OPTION_X264_CRF:
+                       global_flags.x264_crf = atof(optarg);
+                       break;
                case OPTION_X264_VBV_BUFSIZE:
                        global_flags.x264_vbv_buffer_size = atoi(optarg);
                        break;
@@ -481,4 +487,16 @@ void parse_flags(int argc, char * const argv[])
        if (global_flags.max_input_queue_frames > 10) {
                fprintf(stderr, "WARNING: --max-input-queue-frames has little effect over 10.\n");
        }
+
+       if (!isinf(global_flags.x264_crf)) {  // CRF mode is selected.
+               if (global_flags.x264_bitrate != -1) {
+                       fprintf(stderr, "ERROR: --x264-bitrate and --x264-crf are mutually incompatible.\n");
+                       exit(1);
+               }
+               if (global_flags.x264_vbv_max_bitrate != -1 && global_flags.x264_vbv_buffer_size != -1) {
+                       fprintf(stderr, "WARNING: VBV settings are ignored with --x264-crf.\n");
+               }
+       } else if (global_flags.x264_bitrate == -1) {
+               global_flags.x264_bitrate = DEFAULT_X264_OUTPUT_BIT_RATE;
+       }
 }

diff --git a/flags.h b/flags.h
index 6ca9794359904acbb73712440dc3b740a326f170..bd962fe7e4890e1bcc8944ca305cb6fded6f0cde 100644 (file)
--- a/flags.h
+++ b/flags.h
@@ -1,6 +1,8 @@
 #ifndef _FLAGS_H
 #define _FLAGS_H
 
+#include <math.h>
+
 #include <map>
 #include <string>
 #include <vector>
@@ -32,7 +34,8 @@ struct Flags {
        std::string x264_tune = X264_DEFAULT_TUNE;
        bool x264_speedcontrol = false;
        bool x264_speedcontrol_verbose = false;
-       int x264_bitrate = DEFAULT_X264_OUTPUT_BIT_RATE;  // In kilobit/sec.
+       int x264_bitrate = -1;  // In kilobit/sec. -1 = not set = DEFAULT_X264_OUTPUT_BIT_RATE.
+       float x264_crf = HUGE_VAL;  // From 51 - QP_MAX_SPEC to 51. HUGE_VAL = not set = use x264_bitrate instead.
        int x264_vbv_max_bitrate = -1;  // In kilobits. 0 = no limit, -1 = same as <x264_bitrate> (CBR).
        int x264_vbv_buffer_size = -1;  // In kilobits. 0 = one-frame VBV, -1 = same as <x264_bitrate> (one-second VBV).
        std::vector<std::string> x264_extra_param;  // In “key[,value]” format.

diff --git a/mainwindow.cpp b/mainwindow.cpp
index a1c291537fd5031f88fd33320f7c70f104ce4a7a..136890d93826d4b71c276eb896755eb648d9b27c 100644 (file)
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -210,7 +210,7 @@ MainWindow::MainWindow()
        ui->timecode_stream_action->setChecked(global_flags.display_timecode_in_stream);
        ui->timecode_stdout_action->setChecked(global_flags.display_timecode_on_stdout);
 
-       if (global_flags.x264_video_to_http) {
+       if (global_flags.x264_video_to_http && isinf(global_flags.x264_crf)) {
                connect(ui->x264_bitrate_action, &QAction::triggered, this, &MainWindow::x264_bitrate_triggered);
        } else {
                ui->x264_bitrate_action->setEnabled(false);

diff --git a/x264_encoder.cpp b/x264_encoder.cpp
index 0c1ecbc1fbd63c6649d6560da8c846b634695100..dbdef5b1a215e61936eae6d37e78ae47e2591288 100644 (file)
--- a/x264_encoder.cpp
+++ b/x264_encoder.cpp
@@ -30,6 +30,9 @@ namespace {
 
 void update_vbv_settings(x264_param_t *param)
 {
+       if (global_flags.x264_bitrate == -1) {
+               return;
+       }
        if (global_flags.x264_vbv_buffer_size < 0) {
                param->rc.i_vbv_buffer_size = param->rc.i_bitrate;  // One-second VBV.
        } else {
@@ -127,8 +130,13 @@ void X264Encoder::init_x264()
                param.vui.i_colmatrix = 6;  // BT.601/SMPTE 170M.
        }
 
-       param.rc.i_rc_method = X264_RC_ABR;
-       param.rc.i_bitrate = global_flags.x264_bitrate;
+       if (!isinf(global_flags.x264_crf)) {
+               param.rc.i_rc_method = X264_RC_CRF;
+               param.rc.f_rf_constant = global_flags.x264_crf;
+       } else {
+               param.rc.i_rc_method = X264_RC_ABR;
+               param.rc.i_bitrate = global_flags.x264_bitrate;
+       }
        update_vbv_settings(&param);
        if (param.rc.i_vbv_max_bitrate > 0) {
                // If the user wants VBV control to cap the max rate, it is