Move all the FFmpeg RAII helpers into its own file.

[nageru] / image_input.cpp

diff --git a/image_input.cpp b/image_input.cpp
index c9f74f8847c4b5f297c512de57c6d9eed1f7201f..b8e2b02942b4ea01993131f2ee73acf595479e05 100644 (file)
--- a/image_input.cpp
+++ b/image_input.cpp
@@ -18,6 +18,7 @@ extern "C" {
 #include <mutex>
 #include <thread>
 
+#include "ffmpeg_raii.h"
 #include "flags.h"
 
 using namespace std;
@@ -99,50 +100,6 @@ shared_ptr<const ImageInput::Image> ImageInput::load_image(const string &pathnam
        return all_images[pathname];
 }
 
-// Some helpers to make RAII versions of FFmpeg objects.
-// The cleanup functions don't interact all that well with unique_ptr,
-// so things get a bit messy and verbose, but overall it's worth it to ensure
-// we never leak things by accident in error paths.
-
-namespace {
-
-void avformat_close_input_unique(AVFormatContext *format_ctx)
-{
-       avformat_close_input(&format_ctx);
-}
-
-unique_ptr<AVFormatContext, decltype(avformat_close_input_unique)*>
-avformat_open_input_unique(const char *pathname,
-                           AVInputFormat *fmt, AVDictionary **options)
-{
-       AVFormatContext *format_ctx = nullptr;
-       if (avformat_open_input(&format_ctx, pathname, fmt, options) != 0) {
-               format_ctx = nullptr;
-       }
-       return unique_ptr<AVFormatContext, decltype(avformat_close_input_unique)*>(
-               format_ctx, avformat_close_input_unique);
-}
-
-void av_frame_free_unique(AVFrame *frame)
-{
-       av_frame_free(&frame);
-}
-
-unique_ptr<AVFrame, decltype(av_frame_free_unique)*>
-av_frame_alloc_unique()
-{
-       AVFrame *frame = av_frame_alloc();
-       return unique_ptr<AVFrame, decltype(av_frame_free_unique)*>(
-               frame, av_frame_free_unique);
-}
-
-void avcodec_free_context_unique(AVCodecContext *codec_ctx)
-{
-       avcodec_free_context(&codec_ctx);
-}
-
-}  // namespace
-
 shared_ptr<const ImageInput::Image> ImageInput::load_image_raw(const string &pathname)
 {
        // Note: Call before open, not after; otherwise, there's a race.
@@ -179,10 +136,8 @@ shared_ptr<const ImageInput::Image> ImageInput::load_image_raw(const string &pat
        }
 
        const AVCodecParameters *codecpar = format_ctx->streams[stream_index]->codecpar;
-       AVCodecContext *codec_ctx = avcodec_alloc_context3(nullptr);
-       unique_ptr<AVCodecContext, decltype(avcodec_free_context_unique)*> codec_ctx_free(
-               codec_ctx, avcodec_free_context_unique);
-       if (avcodec_parameters_to_context(codec_ctx, codecpar) < 0) {
+       AVCodecContextWithDeleter codec_ctx = avcodec_alloc_context3_unique(nullptr);
+       if (avcodec_parameters_to_context(codec_ctx.get(), codecpar) < 0) {
                fprintf(stderr, "%s: Cannot fill codec parameters\n", pathname.c_str());
                return nullptr;
        }
@@ -191,16 +146,16 @@ shared_ptr<const ImageInput::Image> ImageInput::load_image_raw(const string &pat
                fprintf(stderr, "%s: Cannot find decoder\n", pathname.c_str());
                return nullptr;
        }
-       if (avcodec_open2(codec_ctx, codec, nullptr) < 0) {
+       if (avcodec_open2(codec_ctx.get(), codec, nullptr) < 0) {
                fprintf(stderr, "%s: Cannot open decoder\n", pathname.c_str());
                return nullptr;
        }
        unique_ptr<AVCodecContext, decltype(avcodec_close)*> codec_ctx_cleanup(
-               codec_ctx, avcodec_close);
+               codec_ctx.get(), avcodec_close);
 
        // Read packets until we have a frame or there are none left.
        int frame_finished = 0;
-       auto frame = av_frame_alloc_unique();
+       AVFrameWithDeleter frame = av_frame_alloc_unique();
        bool eof = false;
        do {
                AVPacket pkt;
@@ -213,7 +168,7 @@ shared_ptr<const ImageInput::Image> ImageInput::load_image_raw(const string &pat
                        if (pkt.stream_index != stream_index) {
                                continue;
                        }
-                       if (avcodec_send_packet(codec_ctx, &pkt) < 0) {
+                       if (avcodec_send_packet(codec_ctx.get(), &pkt) < 0) {
                                fprintf(stderr, "%s: Cannot send packet to codec.\n", pathname.c_str());
                                return nullptr;
                        }
@@ -221,7 +176,7 @@ shared_ptr<const ImageInput::Image> ImageInput::load_image_raw(const string &pat
                        eof = true;  // Or error, but ignore that for the time being.
                }
 
-               int err = avcodec_receive_frame(codec_ctx, frame.get());
+               int err = avcodec_receive_frame(codec_ctx.get(), frame.get());
                if (err == 0) {
                        frame_finished = true;
                        break;