Initial commit

src/libs/ajm/ffmpeg_decoder_common.h

@@ -0,0 +1,65 @@
+#pragma once
+
+#include "common/assert.h"
+
+#include <cstdint>
+
+extern "C" {
+#include <libavcodec/avcodec.h>
+#include <libavutil/channel_layout.h>
+#include <libavutil/mem.h>
+#include <libavutil/samplefmt.h>
+#include <libswresample/swresample.h>
+}
+
+namespace Libs::Audio::Ajm {
+
+static AVSampleFormat AjmSampleEncodingToAvFormat(AjmSampleEncoding encoding) {
+	switch (encoding) {
+		case AjmSampleEncoding::S16: return AV_SAMPLE_FMT_S16;
+		case AjmSampleEncoding::S32: return AV_SAMPLE_FMT_S32;
+		case AjmSampleEncoding::Float: return AV_SAMPLE_FMT_FLT;
+		default: EXIT("unsupported AJM PCM sample encoding %u\n", static_cast<uint32_t>(encoding));
+	}
+	return AV_SAMPLE_FMT_S16;
+}
+
+static AVFrame* AjmConvertFfmpegFrame(const AVFrame* frame, AjmSampleEncoding encoding,
+                                      AjmDecodeResult* result) {
+	if (frame == nullptr || result == nullptr) {
+		return nullptr;
+	}
+
+	AVFrame* converted = av_frame_alloc();
+	if (converted == nullptr) {
+		result->result = AJM_RESULT_CODEC_ERROR | AJM_RESULT_FATAL;
+		return nullptr;
+	}
+
+	converted->format      = AjmSampleEncodingToAvFormat(encoding);
+	converted->sample_rate = frame->sample_rate;
+	converted->nb_samples  = frame->nb_samples;
+	if (av_channel_layout_copy(&converted->ch_layout, &frame->ch_layout) < 0 ||
+	    av_frame_get_buffer(converted, 0) < 0) {
+		av_frame_free(&converted);
+		result->result = AJM_RESULT_CODEC_ERROR | AJM_RESULT_FATAL;
+		return nullptr;
+	}
+
+	SwrContext* swr        = nullptr;
+	int         swr_result = swr_alloc_set_opts2(
+	    &swr, &converted->ch_layout, static_cast<AVSampleFormat>(converted->format),
+	    converted->sample_rate, &frame->ch_layout, static_cast<AVSampleFormat>(frame->format),
+	    frame->sample_rate, 0, nullptr);
+	if (swr_result < 0 || swr_init(swr) < 0 || swr_convert_frame(swr, converted, frame) < 0) {
+		swr_free(&swr);
+		av_frame_free(&converted);
+		result->result = AJM_RESULT_CODEC_ERROR | AJM_RESULT_INVALID_DATA;
+		return nullptr;
+	}
+	swr_free(&swr);
+
+	return converted;
+}
+
+} // namespace Libs::Audio::Ajm