refactor(libvideo2x): extracted video frame count estimation into a function

Signed-off-by: k4yt3x <i@k4yt3x.com>

CMakeLists.txt

@@ -309,12 +309,13 @@ list(REMOVE_DUPLICATES ALL_LIBRARIES)
 
 # Create the shared library 'libvideo2x'
 add_library(libvideo2x
+    src/avutils.cpp
     src/conversions.cpp
     src/decoder.cpp
     src/encoder.cpp
     src/fsutils.cpp
-    src/libplacebo_filter.cpp
     src/libplacebo.cpp
+    src/libplacebo_filter.cpp
     src/libvideo2x.cpp
     src/realesrgan_filter.cpp
 )

include/libvideo2x/avutils.h

@@ -0,0 +1,10 @@
+#ifndef AVUTILS_H
+#define AVUTILS_H
+
+extern "C" {
+#include <libavformat/avformat.h>
+}
+
+int64_t get_video_frame_count(AVFormatContext *ifmt_ctx, int in_vstream_idx);
+
+#endif  // AVUTILS_H

src/avutils.cpp

@@ -0,0 +1,50 @@
+#include "avutils.h"
+
+#include <spdlog/spdlog.h>
+
+int64_t get_video_frame_count(AVFormatContext *ifmt_ctx, int in_vstream_idx) {
+    // Use the 'nb_frames' field if it is available
+    int64_t nb_frames = ifmt_ctx->streams[in_vstream_idx]->nb_frames;
+    if (nb_frames != AV_NOPTS_VALUE && nb_frames > 0) {
+        spdlog::debug("Read total number of frames from 'nb_frames': {}", nb_frames);
+        return nb_frames;
+    }
+    spdlog::warn("Estimating the total number of frames from duration * fps");
+
+    // Get the duration of the video
+    double duration_secs = 0.0;
+    if (ifmt_ctx->duration != AV_NOPTS_VALUE) {
+        duration_secs = static_cast<double>(ifmt_ctx->duration) / static_cast<double>(AV_TIME_BASE);
+    } else if (ifmt_ctx->streams[in_vstream_idx]->duration != AV_NOPTS_VALUE) {
+        duration_secs = static_cast<double>(ifmt_ctx->streams[in_vstream_idx]->duration) *
+                        av_q2d(ifmt_ctx->streams[in_vstream_idx]->time_base);
+    }
+    if (duration_secs <= 0) {
+        spdlog::warn("Unable to determine the video's duration");
+        return -1;
+    }
+    spdlog::debug("Video duration: {}s", duration_secs);
+
+    // Calculate average FPS
+    double fps = av_q2d(ifmt_ctx->streams[in_vstream_idx]->avg_frame_rate);
+    if (fps <= 0) {
+        spdlog::debug("Unable to read the average frame rate from 'avg_frame_rate'");
+        fps = av_q2d(ifmt_ctx->streams[in_vstream_idx]->r_frame_rate);
+    }
+    if (fps <= 0) {
+        spdlog::debug("Unable to read the average frame rate from 'r_frame_rate'");
+        fps = av_q2d(av_guess_frame_rate(ifmt_ctx, ifmt_ctx->streams[in_vstream_idx], nullptr));
+    }
+    if (fps <= 0) {
+        spdlog::debug("Unable to estimate the average frame rate with 'av_guess_frame_rate'");
+        fps = av_q2d(ifmt_ctx->streams[in_vstream_idx]->time_base);
+    }
+    if (fps <= 0) {
+        spdlog::warn("Unable to estimate the video's average frame rate");
+        return -1;
+    }
+    spdlog::debug("Video average frame rate: {}", fps);
+
+    // Estimate and return the total number of frames
+    return static_cast<int64_t>(duration_secs * fps);
+}

src/libvideo2x.cpp

@@ -11,6 +11,7 @@ extern "C" {
 
 #include <spdlog/spdlog.h>
 
+#include "avutils.h"
 #include "decoder.h"
 #include "encoder.h"
 #include "filter.h"
@@ -37,46 +38,7 @@ static int process_frames(
 
     // Get the total number of frames in the video with OpenCV
     spdlog::debug("Reading total number of frames");
-    proc_ctx->total_frames = ifmt_ctx->streams[in_vstream_idx]->nb_frames;
+    proc_ctx->total_frames = get_video_frame_count(ifmt_ctx, in_vstream_idx);
-    if (proc_ctx->total_frames > 0) {
-        spdlog::debug("Read total number of frames from 'nb_frames': {}", proc_ctx->total_frames);
-    } else {
-        spdlog::warn("Estimating the total number of frames from duration * fps");
-
-        // Get the duration of the video
-        double duration_secs = 0.0;
-        if (ifmt_ctx->duration != AV_NOPTS_VALUE) {
-            duration_secs =
-                static_cast<double>(ifmt_ctx->duration) / static_cast<double>(AV_TIME_BASE);
-        } else if (ifmt_ctx->streams[in_vstream_idx]->duration != AV_NOPTS_VALUE) {
-            duration_secs = static_cast<double>(ifmt_ctx->streams[in_vstream_idx]->duration) *
-                            av_q2d(ifmt_ctx->streams[in_vstream_idx]->time_base);
-        } else {
-            spdlog::warn("Unable to determine video duration");
-        }
-        spdlog::debug("Video duration: {}s", duration_secs);
-
-        // Calculate average FPS
-        double fps = av_q2d(ifmt_ctx->streams[in_vstream_idx]->avg_frame_rate);
-        if (fps <= 0) {
-            spdlog::debug("Unable to read the average frame rate from 'avg_frame_rate'");
-            fps = av_q2d(ifmt_ctx->streams[in_vstream_idx]->r_frame_rate);
-        }
-        if (fps <= 0) {
-            spdlog::debug("Unable to read the average frame rate from 'r_frame_rate'");
-            fps = av_q2d(av_guess_frame_rate(ifmt_ctx, ifmt_ctx->streams[in_vstream_idx], nullptr));
-        }
-        if (fps <= 0) {
-            spdlog::debug("Unable to estimate the average frame rate with 'av_guess_frame_rate'");
-            fps = av_q2d(ifmt_ctx->streams[in_vstream_idx]->time_base);
-        }
-        if (fps <= 0 || duration_secs <= 0) {
-            spdlog::warn("Unable to estimate the video's average frame rate");
-        } else {
-            // Calculate total frames
-            proc_ctx->total_frames = static_cast<int64_t>(duration_secs * fps);
-        }
-    }
 
     // Check if the total number of frames is still 0
     if (proc_ctx->total_frames <= 0) {

src/video2x.cpp

@@ -676,7 +676,7 @@ int main(int argc, char **argv) {
                 total_frames = proc_ctx.total_frames;
                 pause = proc_ctx.pause;
             }
-            if (!pause && total_frames > 0) {
+            if (!pause && (total_frames > 0 || processed_frames > 0)) {
                 double percentage = total_frames > 0 ? static_cast<double>(processed_frames) *
                                                            100.0 / static_cast<double>(total_frames)
                                                      : 0.0;