build(deps): Raise ffmpeg minimum to 4.0 (released in 2018) (AcademyS…

…oftwareFoundation#4352)

Signed-off-by: Larry Gritz <lg@larrygritz.com>

INSTALL.md

@@ -41,7 +41,7 @@ NEW or CHANGED MINIMUM dependencies since the last major release are **bold**.
  * If you want support for camera "RAW" formats:
      * **LibRaw >= 0.20** (tested though 0.21.2)
  * If you want support for a wide variety of video formats:
-     * ffmpeg >= 3.0 (tested through 7.0)
+     * **ffmpeg >= 4.0** (tested through 7.0)
  * If you want support for jpeg 2000 images:
      * OpenJpeg >= 2.0 (tested through 2.5; we recommend 2.4 or higher
        for multithreading support)

src/cmake/externalpackages.cmake

@@ -161,7 +161,7 @@ checked_find_package (TBB 2017
 # DCMTK is used to read DICOM images
 checked_find_package (DCMTK CONFIG VERSION_MIN 3.6.1)
 
-checked_find_package (FFmpeg VERSION_MIN 3.0)
+checked_find_package (FFmpeg VERSION_MIN 4.0)
 checked_find_package (GIF
                       VERSION_MIN 4
                       RECOMMEND_MIN 5.0

src/ffmpeg.imageio/ffmpeginput.cpp

@@ -2,16 +2,12 @@
 // SPDX-License-Identifier: BSD-3-Clause and Apache-2.0
 // https://github.com/AcademySoftwareFoundation/OpenImageIO
 
-extern "C" {  // ffmpeg is a C api
 #include <cerrno>
+
+extern "C" {  // ffmpeg is a C api
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
 #include <libswscale/swscale.h>
-#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(57, 24, 100)
-#    error "OIIO FFmpeg support requires FFmpeg >= 3.0"
-#endif
-#include <libavutil/imgutils.h>
-}
 
 // It's hard to figure out FFMPEG versions from what they give us, so
 // record some of the milestones once and for all for easy reference.
@@ -29,6 +25,12 @@ extern "C" {  // ffmpeg is a C api
 #define USE_FFMPEG_4_3 (LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(58, 91, 100))
 #define USE_FFMPEG_4_4 (LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(58, 134, 100))
 
+#if !USE_FFMPEG_4_0
+#    error "OIIO FFmpeg support requires FFmpeg >= 4.0"
+#endif
+
+#include <libavutil/imgutils.h>
+}
 
 
 inline int
@@ -41,9 +43,9 @@ avpicture_fill(AVFrame* picture, uint8_t* ptr, enum AVPixelFormat pix_fmt,
 }
 
 
-#if USE_FFMPEG_3_1
-// AVStream::codec was changed to AVStream::codecpar
-#    define stream_codec(ix) m_format_context->streams[(ix)]->codecpar
+#define stream_codec(ix) m_format_context->streams[(ix)]->codecpar
+
+
 // avcodec_decode_video2 was deprecated.
 // This now works by sending `avpkt` to the decoder, which buffers the
 // decoded image in `avctx`. Then `avcodec_receive_frame` will copy the
@@ -65,16 +67,6 @@ receive_frame(AVCodecContext* avctx, AVFrame* picture, AVPacket* avpkt)
 
     return 1;
 }
-#else
-#    define stream_codec(ix) m_format_context->streams[(ix)]->codec
-inline int
-receive_frame(AVCodecContext* avctx, AVFrame* picture, AVPacket* avpkt)
-{
-    int ret;
-    avcodec_decode_video2(avctx, picture, &ret, avpkt);
-    return ret;
-}
-#endif
 
 
 
@@ -265,7 +257,6 @@ FFmpegInput::open(const std::string& name, ImageSpec& spec)
     }
 
     // codec context for videostream
-#if USE_FFMPEG_3_1
     AVCodecParameters* par = stream_codec(m_video_stream);
 
     m_codec = avcodec_find_decoder(par->codec_id);
@@ -287,15 +278,6 @@ FFmpegInput::open(const std::string& name, ImageSpec& spec)
         errorfmt("\"{}\" unsupported codec", file_name);
         return false;
     }
-#else
-    m_codec_context = stream_codec(m_video_stream);
-
-    m_codec = avcodec_find_decoder(m_codec_context->codec_id);
-    if (!m_codec) {
-        errorfmt("\"{}\" unsupported codec", file_name);
-        return false;
-    }
-#endif
 
     if (avcodec_open2(m_codec_context, m_codec, NULL) < 0) {
         errorfmt("\"{}\" could not open codec", file_name);