youtube-dl integration & more intervals

CMakeLists.txt

@@ -8,7 +8,7 @@ project(VidifyAudiosync
 LIST(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 
 # Debug configuration
-set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -Wall -Wextra -g3 -std=c11 \
+set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -Wall -Wextra -g3 -std=c99 \
                          -DDEBUG -fsanitize=undefined -fsanitize=address")
 # Release configuration
 set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -Wall -Wextra -O3")

README.md

@@ -22,6 +22,23 @@ The only exported method is `get_lag(url: str)`, which returns the displacement
 
 There's a simple example implementation in the [example.py](https://github.com/marioortizmanero/vidify-audiosync/blob/master/examples/example.py) file.
 
+There are 2 apps to try:
+
+* `apps/main.c`: used to debug more easily. You can run it with:
+
+```shell
+mkdir build
+cd build
+mkdir images
+cmake ..
+make
+./apps/main "SONG NAME"
+```
+
+Use `-DCMAKE_BUILD_TYPE=Debug` to enable debugging and save plots into the images directory. You'll need `gnuplot` installed for that.
+
+* `apps/main.py`: the actual module usage. You can simply use `python main.py "SONG NAME"`
+
 
 ## How it works
 *I'll try to explain it as clearly as possible, since this took me a lot of effort to understand without prior knowledge about the mathematics behind it. If someone with a better understanding of the calculations performed in this module considers that the explanation could be improved, please [create an issue](https://github.com/marioortizmanero/vidify-audiosync/issues) to let me know.*

apps/CMakeLists.txt

@@ -4,6 +4,6 @@ add_executable(
     ${HEADER_LIST}
 )
 
-target_compile_features(main PRIVATE c_std_11)
+target_compile_features(main PRIVATE c_std_99)
 
 target_link_libraries(main PRIVATE vidify_audiosync fftw3 m pthread)

apps/images/.gitignore

@@ -0,0 +1,5 @@
+# Ignore everything in this directory
+*.png
+
+# Except this file
+!.gitignore

apps/main.c

@@ -5,10 +5,11 @@
 
 int main(int argc, char *argv[]) {
     if (argc != 2) {
-        printf("Usage: %s URL\n", argv[0]);
+        printf("Usage: %s \"TITLE\"\n", argv[0]);
         exit(1);
     }
 
+    printf("Running get_lag\n");
     int ret = get_lag(argv[1]);
     printf("Returned value: %d\n", ret);
 

apps/main.py

@@ -10,15 +10,7 @@
           " background.")
     exit()
 
-# Obtaining an URL from a song name with youtube_dl
-ytdl_opts = {
-    'format': 'bestaudio'
-}
-with youtube_dl.YoutubeDL(ytdl_opts) as ytdl:
-    info = ytdl.extract_info(f"ytsearch:{sys.argv[1]}", download=False)
-url = info['entries'][0]['url']
-
 # After this is printed, the music should start playing in the background too
 print("Running audiosync.get_lag")
-ret = audiosync.get_lag(url)
+ret = audiosync.get_lag(sys.argv[1])
 print(f"Returned value: {ret}")

include/vidify_audiosync/download/linux_download.h

@@ -4,5 +4,7 @@
 
 void *download(void *);
 
+int get_audio_url(char *title, char **url);
+
 
 #endif /* _H_DOWNLOAD_ */

include/vidify_audiosync/global.h

@@ -14,8 +14,10 @@
 // milliseconds.
 #define FRAMES_TO_MS (1000.0 / (double) SAMPLE_RATE)
 
-// The value of the last interval in audiosync.c in seconds.
-#define MAX_SECONDS_STR "15"
+// The value of the last interval in audiosync.c in seconds. This avoids
+// having to run an itoa() for intervals[n_intervals-1] and simplifies it a
+// bit.
+#define MAX_SECONDS_STR "30"
 
 // The minimum cross-correlation coefficient accepted.
 #define MIN_CONFIDENCE 0.75
@@ -32,7 +34,7 @@ struct thread_data {
     int *end;
 };
 struct down_data {
-    char *url;
+    char *yt_title;
     struct thread_data *th_data;
 };
 

src/CMakeLists.txt

@@ -19,8 +19,8 @@ add_library(
 
 target_include_directories(vidify_audiosync PUBLIC ../include)
 
-# C11 is required
-target_compile_features(vidify_audiosync PUBLIC c_std_11)
+# C99 is required
+target_compile_features(vidify_audiosync PUBLIC c_std_99)
 
 # For the IDEs
 source_group(TREE "${PROJECT_SOURCE_DIR}/include" PREFIX "Header Files" FILES ${HEADERS})

src/audiosync.c

@@ -23,7 +23,7 @@
 #include "../include/vidify_audiosync/download/linux_download.h"
 
 
-int get_lag(char *url) {
+int get_lag(char *yt_title) {
     // The audio data.
     double *arr1, *arr2;
     // Variable used to indicate the other threads to end. Any value other
@@ -37,9 +37,10 @@ int get_lag(char *url) {
     const size_t intervals[] = {
         3 * SAMPLE_RATE,  // 144000 frames
         6 * SAMPLE_RATE,  // 288000 frames
-        9 * SAMPLE_RATE,  // 432000 frames
-        12 * SAMPLE_RATE,  // 576000 frames
-        15 * SAMPLE_RATE,  // 720000 frames
+        10 * SAMPLE_RATE,  // 432000 frames
+        15 * SAMPLE_RATE,  // 576000 frames
+        20 * SAMPLE_RATE,  // 720000 frames
+        30 * SAMPLE_RATE,  // 720000 frames
     };
     const size_t n_intervals = sizeof(intervals) / sizeof(intervals[0]);
     const size_t length = intervals[n_intervals-1];
@@ -83,7 +84,7 @@ int get_lag(char *url) {
     // Data structure passed to the download thread. It's a different type
     // because it also needs the url of the video to download.
     struct down_data down_th_params = {
-        .url = url,
+        .yt_title = yt_title,
         .th_data = &down_params
     };
     if (pthread_create(&cap_th, NULL, &capture, (void *) &cap_params) < 0) {

src/bind.c

@@ -23,11 +23,11 @@ PyMODINIT_FUNC PyInit_vidify_audiosync(void) {
 }
 
 PyObject *audiosync_get_lag(PyObject *self, PyObject *args) {
-    char *url;
-    if (!PyArg_ParseTuple(args, "s", &url)) {
+    char *yt_title;
+    if (!PyArg_ParseTuple(args, "s", &yt_title)) {
             return NULL;
     }
 
-    int ret = get_lag(url);
+    int ret = get_lag(yt_title);
     return PyLong_FromLong(ret);
 }

src/capture/linux_capture.c

@@ -3,6 +3,7 @@
 #include <pthread.h>
 #include "../../include/vidify_audiosync/global.h"
 #include "../../include/vidify_audiosync/ffmpeg_pipe.h"
+#include "../../include/vidify_audiosync/capture/linux_capture.h"
 
 
 // NOTE: for now requires to change the captured sink in pavucontrol to

src/cross_correlation.c

@@ -12,7 +12,6 @@
 #include "../include/vidify_audiosync/global.h"
 
 
-
 // Data structure used to pass parameters to concurrent FFTW-related functions.
 struct fftw_data {
     double *real;
@@ -54,6 +53,10 @@ static void *fft(void *thread_arg) {
 // calculate the circular cross-correlation rather than the regular
 // cross-correlation.
 //
+// Note: if debugging mode is enabled, plots of each run will be saved in an
+// images directory. The titles assume that `input1` is the captured data,
+// and `input2` is the downloaded data.
+//
 // Returns the lag in frames the second data set has over the first one, with
 // a confidence between -1 and 1.
 //
@@ -83,13 +86,13 @@ int cross_correlation(double *input1, double *input2, const size_t input_length,
     FILE *gnuplot = popen("gnuplot", "w");
     fprintf(gnuplot, "set term 'png'\n");
     fprintf(gnuplot, "set output 'images/%ld_original.png'\n", input_length);
-    fprintf(gnuplot, "plot '-' with lines title 'data1', '-' with lines title 'data2'\n");
+    fprintf(gnuplot, "plot '-' with lines title 'downloaded', '-' with lines title 'captured'\n");
     for (size_t i = 0; i < input_length; ++i)
-        fprintf(gnuplot, "%f\n", data1[i]);
+        fprintf(gnuplot, "%f\n", data2[i]);
     fprintf(gnuplot, "e\n");
     // The second audio file starts at samplesDelay
     for (size_t i = 0; i < input_length; ++i)
-        fprintf(gnuplot, "%f\n", data2[i]);
+        fprintf(gnuplot, "%f\n", data1[i]);
     fprintf(gnuplot, "e\n");
     fflush(gnuplot);
     pclose(gnuplot);
@@ -207,13 +210,13 @@ int cross_correlation(double *input1, double *input2, const size_t input_length,
     gnuplot = popen("gnuplot", "w");
     fprintf(gnuplot, "set term 'png'\n");
     fprintf(gnuplot, "set output 'images/%ld.png'\n", input_length);
-    fprintf(gnuplot, "plot '-' with lines title 'data1', '-' with lines title 'data2'\n");
+    fprintf(gnuplot, "plot '-' with lines title 'downloaded', '-' with lines title 'captured'\n");
     for (size_t i = 0; i < input_length; ++i)
-        fprintf(gnuplot, "%f\n", data1[i]);
+        fprintf(gnuplot, "%f\n", data2[i]);
     fprintf(gnuplot, "e\n");
     // The second audio file starts at samplesDelay
     for (size_t i = 0; i < input_length; ++i)
-        fprintf(gnuplot, "%f\n", data2[i]);
+        fprintf(gnuplot, "%f\n", data1[i]);
     fprintf(gnuplot, "e\n");
     fflush(gnuplot);
     pclose(gnuplot);

src/download/linux_download.c

@@ -1,20 +1,66 @@
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <pthread.h>
+#include <string.h>
 #include "../../include/vidify_audiosync/global.h"
 #include "../../include/vidify_audiosync/ffmpeg_pipe.h"
+#include "../../include/vidify_audiosync/download/linux_download.h"
+
+#define MAX_LONG_URL 4086
+#define MAX_LONG_COMMAND 4086
 
 
 void *download(void *arg) {
     struct down_data *data;
     data = (struct down_data *) arg;
 
+    char *url = malloc(sizeof(char) * MAX_LONG_URL);
+    if (url == NULL) {
+        perror("malloc");
+        goto finish;
+    }
+
+    if (get_audio_url(data->yt_title, &url) < 0) {
+        fprintf(stderr, "Could not obtain youtube url.\n");
+        goto finish;
+    }
+
     char *args[] = {
-        "ffmpeg", "-y", "-to", "15", "-i", data->url, "-ac",
-        NUM_CHANNELS_STR, "-r", SAMPLE_RATE_STR, "-f", "f64le", "pipe:1",
-        NULL
+        "ffmpeg", "-y", "-to", "15", "-i", url, "-ac", NUM_CHANNELS_STR, "-r",
+        SAMPLE_RATE_STR, "-f", "f64le", "pipe:1", NULL
     };
     read_pipe(data->th_data, args);
 
+finish:
+    if (url) free(url);
     pthread_exit(NULL);
 }
+
+
+// Obtains the audio direct link with Youtube-dl.
+int get_audio_url(char *title, char **url) {
+    int ret = -1;
+
+    // Creating the full command
+    char command[MAX_LONG_COMMAND];
+    strcpy(command, "youtube-dl -g -f bestaudio ytsearch:\"");
+    strcat(command, title);
+    strcat(command, "\"");
+
+    // Run the command and read the output
+    FILE *fp = popen(command, "r");
+    if (fp == NULL) {
+        fprintf(stderr, "Failed to run command\n" );
+        goto finish;
+    }
+    printf("Getting url 1 %s\n", command);
+    fscanf(fp, "%s", *url);
+    printf("Getting url 2\n");
+    pclose(fp);
+
+    ret = 0;
+
+finish:
+    return ret;
+}

tests/CMakeLists.txt

@@ -5,8 +5,8 @@ add_executable(
     ${HEADERS}
 )
 
-# Minimum C11 required. Also listing the used libraries.
-target_compile_features(tests PRIVATE c_std_11)
+# Minimum C99 required. Also listing the used libraries.
+target_compile_features(tests PRIVATE c_std_99)
 target_link_libraries(tests PRIVATE vidify_audiosync fftw3 m pthread)
 
 # Adding the tests one by one for the make command: