movie: replace the old Movie class with a GIF encoder.

doc/tutorial/16_movie.cpp

@@ -17,224 +17,21 @@
 #include <lol/engine.h>
 #include "loldebug.h"
 
-extern "C" {
-#include <libavutil/avassert.h>
-#include <libavutil/channel_layout.h>
-#include <libavutil/mathematics.h>
-#include <libavutil/timestamp.h>
-#include <libavformat/avformat.h>
-#include <libswscale/swscale.h>
-#include <libswresample/swresample.h>
-}
-
-using namespace lol;
-
-class gif_encoder
-{
-public:
-    gif_encoder(ivec2 size)
-      : m_avformat(nullptr),
-        m_avcodec(nullptr),
-        m_stream(nullptr),
-        m_frame(nullptr),
-        m_size(size),
-        m_index(0)
-    {
-        av_register_all();
-        av_log_set_callback(ffmpeg_logger);
-
-        m_frame = av_frame_alloc();
-        ASSERT(m_frame);
-
-        m_frame->format = AV_PIX_FMT_RGB8; // 3:3:2 packed for GIF
-        m_frame->width = m_size.x;
-        m_frame->height = m_size.y;
-
-        int ret = av_frame_get_buffer(m_frame, 32);
-        ASSERT(ret >= 0);
-    }
-
-    bool open_file(char const *filename)
-    {
-        /* Third argument specifies format */
-        avformat_alloc_output_context2(&m_avformat, nullptr, "gif", filename);
-        if (!m_avformat)
-        {
-            msg::debug("could not create output context");
-            return false;
-        }
-
-        if (!open_codec())
-            return false;
-
-        if (!(m_avformat->oformat->flags & AVFMT_NOFILE))
-        {
-            int ret = avio_open(&m_avformat->pb, filename, AVIO_FLAG_WRITE);
-            if (ret < 0)
-            {
-                msg::error("could not open '%s': %s\n", filename, error2string(ret).C());
-                return false;
-            }
-        }
-
-        int ret = avformat_write_header(m_avformat, nullptr);
-        if (ret < 0)
-        {
-            msg::error("could not write header: %s\n", error2string(ret).C());
-            return false;
-        }
-
-        return true;
-    }
-
-    bool push_image(image &im)
-    {
-        // Make sure the encoder does not hold a reference on our
-        // frame (GIF does that in order to compress using deltas).
-        if (av_frame_make_writable(m_frame) < 0)
-            return false;
-
-        // Convert image to 3:3:2. TODO: add some dithering
-        u8vec3 *data = im.lock<PixelFormat::RGB_8>();
-        for (int n = 0; n < im.size().x * im.size().y; ++n)
-            m_frame->data[0][n] = (data[n].r & 0xe0) | ((data[n].g & 0xe0) >> 3) | (data[n].b >> 6);
-        im.unlock(data);
-
-        m_frame->pts = m_index++;
-
-        AVPacket pkt;
-        memset(&pkt, 0, sizeof(pkt));
-        av_init_packet(&pkt);
-
-        // XXX: is got_packet necessary?
-        int got_packet = 0;
-        int ret = avcodec_encode_video2(m_avcodec, &pkt, m_frame, &got_packet);
-        if (ret < 0)
-        {
-            msg::error("cannot encode video frame: %s\n", error2string(ret).C());
-            return false;
-        }
-
-        if (got_packet)
-        {
-            pkt.stream_index = m_stream->index;
-
-            ret = av_interleaved_write_frame(m_avformat, &pkt);
-            if (ret < 0)
-            {
-                msg::error("cannot write video frame: %s\n", error2string(ret).C());
-                return false;
-            }
-        }
-
-        return true;
-    }
-
-    void close()
-    {
-        // this must be done before m_avcodec is freed
-        av_write_trailer(m_avformat);
-
-        avcodec_free_context(&m_avcodec);
-        av_frame_free(&m_frame);
-
-        if (!(m_avformat->oformat->flags & AVFMT_NOFILE))
-            avio_closep(&m_avformat->pb);
-
-        avformat_free_context(m_avformat);
-    }
-
-private:
-    bool open_codec()
-    {
-        AVCodec *codec = avcodec_find_encoder(m_avformat->oformat->video_codec);
-        if (!codec)
-        {
-            msg::error("no encoder found for %s\n", avcodec_get_name(m_avformat->oformat->video_codec));
-            return false;
-        }
-
-        m_stream = avformat_new_stream(m_avformat, nullptr);
-        if (!m_stream)
-        {
-            msg::error("cannot allocate stream\n");
-            return false;
-        }
-        m_stream->id = 0; // first (and only?) stream
-        m_stream->time_base = AVRational{ 1, 30 }; // 30 fps
-
-        m_avcodec = avcodec_alloc_context3(codec);
-        if (!m_avcodec)
-        {
-            msg::error("cannot allocate encoding context\n");
-            return false;
-        }
-
-        m_avcodec->codec_id = m_avformat->oformat->video_codec;
-        m_avcodec->width = m_frame->width;
-        m_avcodec->height = m_frame->height;
-        m_avcodec->pix_fmt = AVPixelFormat(m_frame->format);
-        m_avcodec->time_base = m_stream->time_base;
-
-        if (m_avformat->oformat->flags & AVFMT_GLOBALHEADER)
-            m_avcodec->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
-
-        int ret = avcodec_open2(m_avcodec, codec, nullptr);
-        if (ret < 0)
-        {
-            msg::error("cannot open video codec: %s\n", error2string(ret).C());
-            return false;
-        }
-
-        ret = avcodec_parameters_from_context(m_stream->codecpar, m_avcodec);
-        if (ret < 0)
-        {
-            msg::error("cannot copy stream parameters\n");
-            return false;
-        }
-
-        return true;
-    }
-
-    static String error2string(int errnum)
-    {
-        char tmp[AV_ERROR_MAX_STRING_SIZE];
-        av_strerror(errnum, tmp, AV_ERROR_MAX_STRING_SIZE);
-        return String(tmp);
-    }
-
-    static void ffmpeg_logger(void *ptr, int level, const char *fmt, va_list vl)
-    {
-        // FIXME: use lol::msg::debug
-        UNUSED(ptr, level);
-        vfprintf(stderr, fmt, vl);
-    }
-
-private:
-    AVFormatContext *m_avformat;
-    AVCodecContext *m_avcodec;
-    AVStream *m_stream;
-    AVFrame *m_frame;
-    ivec2 m_size;
-    int m_index;
-};
-
-
 int main(int argc, char **argv)
 {
     UNUSED(argc, argv);
 
-    ivec2 size(256, 256);
+    lol::ivec2 size(256, 256);
 
-    gif_encoder enc(size);
-    if (!enc.open_file("16_movie.gif"))
+    lol::movie movie(size);
+    if (!movie.open_file("16_movie.gif"))
         return EXIT_FAILURE;
 
     for (int i = 0; i < 256; ++i)
     {
-        image im(size);
+        lol::image im(size);
 
-        array2d<u8vec3> &data = im.lock2d<PixelFormat::RGB_8>();
+        lol::array2d<lol::u8vec3> &data = im.lock2d<lol::PixelFormat::RGB_8>();
         for (int y = 0; y < size.y; ++y)
         for (int x = 0; x < size.x; ++x)
         {
@@ -244,11 +41,11 @@ int main(int argc, char **argv)
         }
         im.unlock2d(data);
 
-        if (!enc.push_image(im))
+        if (!movie.push_image(im))
             break;
     }
 
-    enc.close();
+    movie.close();
 
     return 0;
 }

src/image/movie.cpp

@@ -1,7 +1,7 @@
 //
 //  Lol Engine
 //
-//  Copyright © 2010—2016 Sam Hocevar <sam@hocevar.net>
+//  Copyright © 2010—2017 Sam Hocevar <sam@hocevar.net>
 //
 //  Lol Engine is free software. It comes without any warranty, to
 //  the extent permitted by applicable law. You can redistribute it
@@ -15,7 +15,13 @@
 #if LOL_USE_FFMPEG
 extern "C"
 {
+#   include <libavutil/avassert.h>
+#   include <libavutil/channel_layout.h>
+#   include <libavutil/mathematics.h>
+#   include <libavutil/timestamp.h>
 #   include <libavformat/avformat.h>
+#   include <libswscale/swscale.h>
+#   include <libswresample/swresample.h>
 }
 #endif
 
@@ -23,49 +29,194 @@ namespace lol
 {
 
 #if LOL_USE_FFMPEG
-static bool g_ready = false;
+#define ERROR_TO_STRING(errnum) (error2string((errnum)).C())
+static String error2string(int errnum)
+{
+    char tmp[AV_ERROR_MAX_STRING_SIZE];
+    av_strerror(errnum, tmp, AV_ERROR_MAX_STRING_SIZE);
+    return String(tmp);
+}
+
+static void ffmpeg_logger(void *ptr, int level, const char *fmt, va_list vl)
+{
+    // FIXME: use lol::msg::debug
+    UNUSED(ptr, level);
+    vfprintf(stderr, fmt, vl);
+}
 #endif
 
-class MovieData
+movie::movie(ivec2 size)
+  : m_avformat(nullptr),
+    m_avcodec(nullptr),
+    m_stream(nullptr),
+    m_frame(nullptr),
+    m_size(size),
+    m_index(0)
 {
 #if LOL_USE_FFMPEG
+    av_register_all();
+    //av_log_set_callback(ffmpeg_logger);
 
-#endif
+    m_frame = av_frame_alloc();
+    ASSERT(m_frame);
 
-    friend class Movie;
-};
+    m_frame->format = AV_PIX_FMT_RGB8; // 3:3:2 packed for GIF
+    m_frame->width = m_size.x;
+    m_frame->height = m_size.y;
 
-/*
- * Public Movie class
- */
+    int ret = av_frame_get_buffer(m_frame, 32);
+    ASSERT(ret >= 0);
+#endif
+}
 
-Movie::Movie(String const &name, ivec2 size, float fps)
-  : m_data(new MovieData())
+bool movie::open_file(char const *filename)
 {
 #if LOL_USE_FFMPEG
-    if (!g_ready)
+    /* Third argument specifies format */
+    avformat_alloc_output_context2(&m_avformat, nullptr, "gif", filename);
+    if (!m_avformat)
+    {
+        msg::debug("could not create output context");
+        return false;
+    }
+
+    if (!open_codec())
+        return false;
+
+    if (!(m_avformat->oformat->flags & AVFMT_NOFILE))
+    {
+        int ret = avio_open(&m_avformat->pb, filename, AVIO_FLAG_WRITE);
+        if (ret < 0)
+        {
+            msg::error("could not open '%s': %s\n", filename, ERROR_TO_STRING(ret));
+            return false;
+        }
+    }
+
+    int ret = avformat_write_header(m_avformat, nullptr);
+    if (ret < 0)
     {
-        g_ready = true;
-        av_register_all();
+        msg::error("could not write header: %s\n", ERROR_TO_STRING(ret));
+        return false;
     }
 #endif
+
+    return true;
 }
 
-Movie::~Movie()
+bool movie::push_image(image &im)
 {
 #if LOL_USE_FFMPEG
+    // Make sure the encoder does not hold a reference on our
+    // frame (GIF does that in order to compress using deltas).
+    if (av_frame_make_writable(m_frame) < 0)
+        return false;
+
+    // Convert image to 3:3:2. TODO: add some dithering
+    u8vec3 *data = im.lock<PixelFormat::RGB_8>();
+    for (int n = 0; n < im.size().x * im.size().y; ++n)
+        m_frame->data[0][n] = (data[n].r & 0xe0) | ((data[n].g & 0xe0) >> 3) | (data[n].b >> 6);
+    im.unlock(data);
+
+    m_frame->pts = m_index++;
+
+    AVPacket pkt;
+    memset(&pkt, 0, sizeof(pkt));
+    av_init_packet(&pkt);
+
+    // XXX: is got_packet necessary?
+    int got_packet = 0;
+    int ret = avcodec_encode_video2(m_avcodec, &pkt, m_frame, &got_packet);
+    if (ret < 0)
+    {
+        msg::error("cannot encode video frame: %s\n", ERROR_TO_STRING(ret));
+        return false;
+    }
 
+    if (got_packet)
+    {
+        pkt.stream_index = m_stream->index;
+
+        ret = av_interleaved_write_frame(m_avformat, &pkt);
+        if (ret < 0)
+        {
+            msg::error("cannot write video frame: %s\n", ERROR_TO_STRING(ret));
+            return false;
+        }
+    }
 #endif
 
-    delete m_data;
+    return true;
+}
+
+void movie::close()
+{
+#if LOL_USE_FFMPEG
+    // this must be done before m_avcodec is freed
+    av_write_trailer(m_avformat);
+
+    avcodec_free_context(&m_avcodec);
+    av_frame_free(&m_frame);
+
+    if (!(m_avformat->oformat->flags & AVFMT_NOFILE))
+        avio_closep(&m_avformat->pb);
+
+    avformat_free_context(m_avformat);
+#endif
 }
 
-void Movie::Feed(image const &image)
+bool movie::open_codec()
 {
 #if LOL_USE_FFMPEG
+    AVCodec *codec = avcodec_find_encoder(m_avformat->oformat->video_codec);
+    if (!codec)
+    {
+        msg::error("no encoder found for %s\n", avcodec_get_name(m_avformat->oformat->video_codec));
+        return false;
+    }
+
+    m_stream = avformat_new_stream(m_avformat, nullptr);
+    if (!m_stream)
+    {
+        msg::error("cannot allocate stream\n");
+        return false;
+    }
+    m_stream->id = 0; // first (and only?) stream
+    m_stream->time_base = AVRational{ 1, 30 }; // 30 fps
 
+    m_avcodec = avcodec_alloc_context3(codec);
+    if (!m_avcodec)
+    {
+        msg::error("cannot allocate encoding context\n");
+        return false;
+    }
+
+    m_avcodec->codec_id = m_avformat->oformat->video_codec;
+    m_avcodec->width = m_frame->width;
+    m_avcodec->height = m_frame->height;
+    m_avcodec->pix_fmt = AVPixelFormat(m_frame->format);
+    m_avcodec->time_base = m_stream->time_base;
+
+    if (m_avformat->oformat->flags & AVFMT_GLOBALHEADER)
+        m_avcodec->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
+
+    int ret = avcodec_open2(m_avcodec, codec, nullptr);
+    if (ret < 0)
+    {
+        msg::error("cannot open video codec: %s\n", ERROR_TO_STRING(ret));
+        return false;
+    }
+
+    ret = avcodec_parameters_from_context(m_stream->codecpar, m_avcodec);
+    if (ret < 0)
+    {
+        msg::error("cannot copy stream parameters\n");
+        return false;
+    }
 #endif
+
+    return true;
 }
 
-} /* namespace lol */
+} // namespace lol
 

src/lol/image/movie.h

@@ -1,7 +1,7 @@
 //
 //  Lol Engine
 //
-//  Copyright © 2010—2015 Sam Hocevar <sam@hocevar.net>
+//  Copyright © 2010—2017 Sam Hocevar <sam@hocevar.net>
 //
 //  Lol Engine is free software. It comes without any warranty, to
 //  the extent permitted by applicable law. You can redistribute it
@@ -13,32 +13,41 @@
 #pragma once
 
 //
-// The Movie class
+// The movie class
 // ---------------
 //
 
-#include <lol/image/movie.h>
+#include <lol/image/pixel.h>
+#include <lol/image/image.h>
+
+extern "C" struct AVFormatContext;
+extern "C" struct AVCodecContext;
+extern "C" struct AVStream;
+extern "C" struct AVFrame;
 
 namespace lol
 {
 
-class Movie
+class movie
 {
 public:
-    Movie(String const &name, ivec2 size, float fps);
+    movie(ivec2 size);
 
-    /* TODO: Rule of three */
-#if 0
-    Movie(Movie const &other);
-    Movie & operator =(Movie other);
-#endif
-    ~Movie();
+    bool open_file(char const *filename);
+    bool push_image(image &im);
+    void close();
 
-    void Feed(image const &image);
+private:
+    bool open_codec();
 
 private:
-    class MovieData *m_data;
+    AVFormatContext *m_avformat;
+    AVCodecContext *m_avcodec;
+    AVStream *m_stream;
+    AVFrame *m_frame;
+    ivec2 m_size;
+    int m_index;
 };
 
-} /* namespace lol */
+} // namespace lol