Proper inspection of audio frames; support for audio tolerance.

1 files changed, 93 insertions, 4 deletions

diff --git a/ffcmp.c b/ffcmp.c
index 786ad949..0ba9af80 100644
--- a/ffcmp.c
+++ b/ffcmp.c
@@ -1,5 +1,6 @@
 #include <libavformat/avformat.h>
 #include <libavutil/frame.h>
+#include <getopt.h>
 #include <stdbool.h>
 
 #define MAX_COMPLETE_FRAMES 64
@@ -112,13 +113,51 @@ read_frame(File* file)
 	return false;
 }
 
+void help(char const * name)
+{
+	fprintf(stderr, "Syntax: %s [options] file1 file2\n", name);
+	fprintf(stderr, "Options are:\n");
+	fprintf(stderr, "\t--audio-sample-tolerance, -t  specify allowable absolute difference in audio sample value\n");
+}
+
 int main(int argc, char** argv)
 {
+	int audio_sample_tolerance = 0;
+
+	int option_index = 0;
+	while (true) {
+		static struct option long_options[] = {
+			{ "help", no_argument, 0, 'h' },
+			{ "audio-sample-tolerance", required_argument, 0, 't' },
+			{ 0, 0, 0, 0 }
+		};
+
+		int c = getopt_long(argc, argv, "ht:", long_options, &option_index);
+
+		if (c == -1) {
+			break;
+		}
+
+		switch (c) {
+		case 'h':
+			help(argv[0]);
+			break;
+		case 't':
+			audio_sample_tolerance = atoi(optarg);
+			break;
+		}
+	}
+
+	if (argc - optind < 2 || argc - optind >= 3) {
+		help(argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
 	av_register_all();
 
 	File file[2] = {
-		open_file(argv[1]),
-		open_file(argv[2])
+		open_file(argv[optind]),
+		open_file(argv[optind + 1])
 	};
 
 	if (file[0].format_context->nb_streams != file[1].format_context->nb_streams) {
@@ -148,12 +187,62 @@ int main(int argc, char** argv)
 			Frame frame = file[0].complete_frames[0];
 			AVStream* stream = file[0].format_context->streams[frame.stream_index];
 
+			if (
+				file[0].format_context->streams[file[0].complete_frames[0].stream_index]->codec->sample_fmt !=
+				file[1].format_context->streams[file[1].complete_frames[0].stream_index]->codec->sample_fmt) {
+				fprintf(stderr, "Audio sample formats differ.\n");
+				exit(EXIT_FAILURE);
+			}
+
+			if (
+				file[0].format_context->streams[file[0].complete_frames[0].stream_index]->codec->channels !=
+				file[1].format_context->streams[file[1].complete_frames[0].stream_index]->codec->channels) {
+				fprintf(stderr, "Audio channel counts differ.\n");
+				exit(EXIT_FAILURE);
+			}
+
+			if (
+				file[0].complete_frames[0].frame->nb_samples !=
+				file[1].complete_frames[0].frame->nb_samples) {
+				fprintf(stderr, "Audio frame counts differ.\n");
+				exit(EXIT_FAILURE);
+			}
+
 			int const size = av_samples_get_buffer_size(0, stream->codec->channels, frame.frame->nb_samples, stream->codec->sample_fmt, 1);
 			int const check = av_sample_fmt_is_planar(stream->codec->sample_fmt) ? stream->codec->channels : 1;
 			for (int i = 0; i < check; ++i) {
 				if (memcmp(file[0].complete_frames[0].frame->data[i], file[1].complete_frames[0].frame->data[i], size) != 0) {
-					fprintf(stderr, "Audio frames %d differ.\n", file[0].complete_frame_index);
-					exit(EXIT_FAILURE);
+
+					int const channels = file[0].format_context->streams[file[0].complete_frames[0].stream_index]->codec->channels;
+					int const frames = frame.frame->nb_samples;
+
+					bool different = false;
+					switch (stream->codec->sample_fmt) {
+					case AV_SAMPLE_FMT_S16:
+					{
+						int16_t* p = (int16_t *) (file[0].complete_frames[0].frame->data[0]);
+						int16_t* q = (int16_t *) (file[1].complete_frames[0].frame->data[0]);
+						for (int i = 0; i < channels; ++i) {
+							for (int j = 0; j < frames; ++j) {
+								if (abs(*p - *q) > audio_sample_tolerance) {
+									different = true;
+									fprintf(stderr, "\tsamples %d vs %d at channel %d frame %d\n", *p, *q, i, j);
+								}
+								++p;
+								++q;
+							}
+						}
+						break;
+					}
+					default:
+						fprintf(stderr, "Audio frames differ and could not be compared in detail.\n");
+						break;
+					}
+
+					if (different) {
+						fprintf(stderr, "Audio frames %d differ.\n", file[0].complete_frame_index);
+						exit(EXIT_FAILURE);
+					}
 				}
 			}