X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=nageru%2Fffmpeg_capture.cpp;h=5cf1d8c9ec75f35a6932a6bd7a282914c3017d92;hb=cb1dcf409cde897b011e9d9d3cd3cf2974956190;hp=0dea5598555921c401d8e3d463796dc3edaad9f6;hpb=7092d222bb356549ef453f9c6f0b21123fd8a2ce;p=nageru

diff --git a/nageru/ffmpeg_capture.cpp b/nageru/ffmpeg_capture.cpp
index 0dea559..5cf1d8c 100644
--- a/nageru/ffmpeg_capture.cpp
+++ b/nageru/ffmpeg_capture.cpp
@@ -26,6 +26,7 @@ extern "C" {
 #include <cstdint>
 #include <utility>
 #include <vector>
+#include <unordered_set>
 
 #include <Eigen/Core>
 #include <Eigen/LU>
@@ -457,22 +458,60 @@ void FFmpegCapture::send_disconnected_frame()
 template<AVHWDeviceType type>
 AVPixelFormat get_hw_format(AVCodecContext *ctx, const AVPixelFormat *fmt)
 {
-	for (const AVPixelFormat *fmt_ptr = fmt; *fmt_ptr != -1; ++fmt_ptr) {
-		for (int i = 0;; ++i) {  // Termination condition inside loop.
-			const AVCodecHWConfig *config = avcodec_get_hw_config(ctx->codec, i);
-			if (config == nullptr) {  // End of list.
-				fprintf(stderr, "Decoder %s does not support device.\n", ctx->codec->name);
-				break;
-			}
-			if (config->methods & AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX &&
-			    config->device_type == type &&
-			    config->pix_fmt == *fmt_ptr) {
+	bool found_config_of_right_type = false;
+	for (int i = 0;; ++i) {  // Termination condition inside loop.
+		const AVCodecHWConfig *config = avcodec_get_hw_config(ctx->codec, i);
+		if (config == nullptr) {  // End of list.
+			break;
+		}
+		if (!(config->methods & AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX) ||
+		    config->device_type != type) {
+			// Not interesting for us.
+			continue;
+		}
+
+		// We have a config of the right type, but does it actually support
+		// the pixel format we want? (Seemingly, FFmpeg's way of signaling errors
+		// is to just replace the pixel format with a software-decoded one,
+		// such as yuv420p.)
+		found_config_of_right_type = true;
+		for (const AVPixelFormat *fmt_ptr = fmt; *fmt_ptr != -1; ++fmt_ptr) {
+			if (config->pix_fmt == *fmt_ptr) {
+				fprintf(stderr, "Initialized '%s' hardware decoding for codec '%s'.\n",
+					av_hwdevice_get_type_name(type), ctx->codec->name);
+				if (ctx->profile == FF_PROFILE_H264_BASELINE) {
+					fprintf(stderr, "WARNING: Stream claims to be H.264 Baseline, which is generally poorly supported in hardware decoders.\n");
+					fprintf(stderr, "         Consider encoding it as Constrained Baseline, Main or High instead.\n");
+					fprintf(stderr, "         Decoding might fail and fall back to software.\n");
+				}
 				return config->pix_fmt;
 			}
 		}
+		fprintf(stderr, "Decoder '%s' supports only these pixel formats:", ctx->codec->name);
+		unordered_set<AVPixelFormat> seen;
+		for (const AVPixelFormat *fmt_ptr = fmt; *fmt_ptr != -1; ++fmt_ptr) {
+			if (!seen.count(*fmt_ptr)) {
+				fprintf(stderr, " %s", av_get_pix_fmt_name(*fmt_ptr));
+				seen.insert(*fmt_ptr);
+			}
+		}
+		fprintf(stderr, " (wanted %s for hardware acceleration)\n", av_get_pix_fmt_name(config->pix_fmt));
+
+	}
+
+	if (!found_config_of_right_type) {
+		fprintf(stderr, "Decoder '%s' does not support device type '%s'.\n", ctx->codec->name, av_hwdevice_get_type_name(type));
+	}
+
+	// We found no VA-API formats, so take the first software format.
+	for (const AVPixelFormat *fmt_ptr = fmt; *fmt_ptr != -1; ++fmt_ptr) {
+		if ((av_pix_fmt_desc_get(*fmt_ptr)->flags & AV_PIX_FMT_FLAG_HWACCEL) == 0) {
+			fprintf(stderr, "Falling back to software format %s.\n", av_get_pix_fmt_name(*fmt_ptr));
+			return *fmt_ptr;
+		}
 	}
 
-	// We found no VA-API formats, so take the best software format.
+	// Fallback: Just return anything. (Should never really happen.)
 	return fmt[0];
 }