zoneminder/src/zm_ffmpeg_camera.cpp

//
// ZoneMinder Ffmpeg Camera Class Implementation
// Copyright (C) 2001-2008 Philip Coombes
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//

#include "zm.h"
#include "zm_signal.h"
#include "zm_utils.h"

#if HAVE_LIBAVFORMAT

#include "zm_ffmpeg_camera.h"

extern "C" {
#include "libavutil/time.h"
#if HAVE_LIBAVUTIL_HWCONTEXT_H
  #include "libavutil/hwcontext.h"
#endif

#include "libavutil/pixdesc.h"
}

#include <string>
#include <locale>

#if HAVE_LIBAVUTIL_HWCONTEXT_H
#if LIBAVCODEC_VERSION_CHECK(57, 89, 0, 89, 0)
static enum AVPixelFormat hw_pix_fmt;
static enum AVPixelFormat get_hw_format(
    AVCodecContext *ctx,
    const enum AVPixelFormat *pix_fmts
) {
  const enum AVPixelFormat *p;

  for ( p = pix_fmts; *p != -1; p++ ) {
    if ( *p == hw_pix_fmt )
      return *p;
  }

  Error("Failed to get HW surface format for %s.",
      av_get_pix_fmt_name(hw_pix_fmt));
  for ( p = pix_fmts; *p != -1; p++ )
    Error("Available HW surface format was %s.",
        av_get_pix_fmt_name(*p));

  return AV_PIX_FMT_NONE;
}
#if !LIBAVUTIL_VERSION_CHECK(56, 22, 0, 14, 0)
static enum AVPixelFormat find_fmt_by_hw_type(const enum AVHWDeviceType type) {
  enum AVPixelFormat fmt;
  switch (type) {
    case AV_HWDEVICE_TYPE_VAAPI:
      fmt = AV_PIX_FMT_VAAPI;
      break;
    case AV_HWDEVICE_TYPE_DXVA2:
      fmt = AV_PIX_FMT_DXVA2_VLD;
      break;
    case AV_HWDEVICE_TYPE_D3D11VA:
      fmt = AV_PIX_FMT_D3D11;
      break;
    case AV_HWDEVICE_TYPE_VDPAU:
      fmt = AV_PIX_FMT_VDPAU;
      break;
    case AV_HWDEVICE_TYPE_CUDA:
      fmt = AV_PIX_FMT_CUDA;
      break;
    case AV_HWDEVICE_TYPE_VIDEOTOOLBOX:
      fmt = AV_PIX_FMT_VIDEOTOOLBOX;
      break;
    default:
      fmt = AV_PIX_FMT_NONE;
      break;
  }
  return fmt;
}
#endif
#endif
#endif

FfmpegCamera::FfmpegCamera(
    int p_id,
    const std::string &p_path,
    const std::string &p_method,
    const std::string &p_options,
    int p_width,
    int p_height,
    int p_colours,
    int p_brightness,
    int p_contrast,
    int p_hue,
    int p_colour,
    bool p_capture,
    bool p_record_audio,
    const std::string &p_hwaccel_name,
    const std::string &p_hwaccel_device) :
  Camera(
      p_id,
      FFMPEG_SRC,
      p_width,
      p_height,
      p_colours,
      ZM_SUBPIX_ORDER_DEFAULT_FOR_COLOUR(p_colours),
      p_brightness,
      p_contrast,
      p_hue,
      p_colour,
      p_capture,
      p_record_audio
      ),
  mPath(p_path),
  mMethod(p_method),
  mOptions(p_options),
  hwaccel_name(p_hwaccel_name),
  hwaccel_device(p_hwaccel_device)
{
  if ( capture ) {
    FFMPEGInit();
  }

  mFormatContext = nullptr;
  mVideoStreamId = -1;
  mAudioStreamId = -1;
  mVideoCodecContext = nullptr;
  mAudioCodecContext = nullptr;
  mVideoCodec = nullptr;
  mAudioCodec = nullptr;
  mRawFrame = nullptr;
  mFrame = nullptr;
  frameCount = 0;
  mCanCapture = false;
  error_count = 0;
  use_hwaccel = true;
#if HAVE_LIBAVUTIL_HWCONTEXT_H
  hwFrame = nullptr;
  hw_device_ctx = nullptr;
#if LIBAVCODEC_VERSION_CHECK(57, 89, 0, 89, 0)
  hw_pix_fmt = AV_PIX_FMT_NONE;
#endif
#endif

#if HAVE_LIBSWSCALE
  mConvertContext = nullptr;
#endif
  /* Has to be located inside the constructor so other components such as zma
   * will receive correct colours and subpixel order */
  if ( colours == ZM_COLOUR_RGB32 ) {
    subpixelorder = ZM_SUBPIX_ORDER_RGBA;
    imagePixFormat = AV_PIX_FMT_RGBA;
  } else if ( colours == ZM_COLOUR_RGB24 ) {
    subpixelorder = ZM_SUBPIX_ORDER_RGB;
    imagePixFormat = AV_PIX_FMT_RGB24;
  } else if ( colours == ZM_COLOUR_GRAY8 ) {
    subpixelorder = ZM_SUBPIX_ORDER_NONE;
    imagePixFormat = AV_PIX_FMT_GRAY8;
  } else {
    Panic("Unexpected colours: %d", colours);
  }

  frame_buffer = nullptr;
  // sws_scale needs 32bit aligned width and an extra 16 bytes padding, so recalculate imagesize, which was width*height*bytes_per_pixel
#if LIBAVUTIL_VERSION_CHECK(54, 6, 0, 6, 0)
  alignment = 32;
  imagesize = av_image_get_buffer_size(imagePixFormat, width, height, alignment);
  // av_image_get_linesize isn't aligned, so we have to do that.
  linesize = FFALIGN(av_image_get_linesize(imagePixFormat, width, 0), alignment);
#else
  alignment = 1;
  linesize = FFALIGN(av_image_get_linesize(imagePixFormat, width, 0), alignment);
  imagesize = avpicture_get_size(imagePixFormat, width, height);
#endif
  if ( linesize != width * colours ) {
    Debug(1, "linesize %d != width %d * colours %d = %d, allocating frame_buffer", linesize, width, colours, width*colours);
    frame_buffer = (uint8_t *)av_malloc(imagesize);
  }

  Debug(1, "ffmpegcamera: width %d height %d linesize %d colours %d image linesize %d imagesize %d",
      width, height, linesize, colours, width*colours, imagesize);
}  // FfmpegCamera::FfmpegCamera

FfmpegCamera::~FfmpegCamera() {
  Close();

  FFMPEGDeInit();
}

int FfmpegCamera::PrimeCapture() {
  if ( mCanCapture ) {
    Debug(1, "Priming capture from %s, Closing", mPath.c_str());
    Close();
  }
  mVideoStreamId = -1;
  mAudioStreamId = -1;
  Debug(1, "Priming capture from %s", mPath.c_str());

  return OpenFfmpeg();
}

int FfmpegCamera::PreCapture() {
  return 0;
}

int FfmpegCamera::Capture(ZMPacket &zm_packet) {
  if ( !mCanCapture )
    return -1;

  int ret;

  if ( (ret = av_read_frame(mFormatContext, &packet)) < 0 ) {
    if (
        // Check if EOF.
        (ret == AVERROR_EOF || (mFormatContext->pb && mFormatContext->pb->eof_reached)) ||
        // Check for Connection failure.
        (ret == -110)
       ) {
      Info("Unable to read packet from stream %d: error %d \"%s\".",
          packet.stream_index, ret, av_make_error_string(ret).c_str());
    } else {
      Error("Unable to read packet from stream %d: error %d \"%s\".",
          packet.stream_index, ret, av_make_error_string(ret).c_str());
    }
    return -1;
  }
  dumpPacket(mFormatContext->streams[packet.stream_index], &packet, "ffmpeg_camera in");

#if LIBAVCODEC_VERSION_CHECK(57, 64, 0, 64, 0)
  //audio_packet->codec_type = camera->get_AudioStream()->codecpar->codec_type;
  zm_packet.codec_type = mFormatContext->streams[packet.stream_index]->codecpar->codec_type;
#else
  zm_packet.codec_type = mFormatContext->streams[packet.stream_index]->codec->codec_type;
  //audio_packet->codec_type = camera->get_AudioStream()->codec->codec_type;
#endif
  bytes += packet.size;
  zm_packet.set_packet(&packet);
  zm_av_packet_unref(&packet);
  return 1;
} // FfmpegCamera::Capture

int FfmpegCamera::PostCapture() {
  // Nothing to do here
  return 0;
}

int FfmpegCamera::OpenFfmpeg() {
  int ret;

  error_count = 0;

  // Open the input, not necessarily a file
#if !LIBAVFORMAT_VERSION_CHECK(53, 2, 0, 4, 0)
  if ( av_open_input_file(&mFormatContext, mPath.c_str(), nullptr, 0, nullptr) != 0 )
#else
  // Handle options
  AVDictionary *opts = nullptr;
  ret = av_dict_parse_string(&opts, Options().c_str(), "=", ",", 0);
  if ( ret < 0 ) {
    Warning("Could not parse ffmpeg input options '%s'", Options().c_str());
  }

  // Set transport method as specified by method field, rtpUni is default
  std::string protocol = mPath.substr(0, 4);
  string_toupper(protocol);
  if ( protocol == "RTSP" ) {
    const std::string method = Method();
    if ( method == "rtpMulti" ) {
      ret = av_dict_set(&opts, "rtsp_transport", "udp_multicast", 0);
    } else if ( method == "rtpRtsp" ) {
      ret = av_dict_set(&opts, "rtsp_transport", "tcp", 0);
    } else if ( method == "rtpRtspHttp" ) {
      ret = av_dict_set(&opts, "rtsp_transport", "http", 0);
    } else if ( method == "rtpUni" ) {
      ret = av_dict_set(&opts, "rtsp_transport", "udp", 0);
    } else {
      Warning("Unknown method (%s)", method.c_str());
    }
    if ( ret < 0 ) {
      Warning("Could not set rtsp_transport method '%s'", method.c_str());
    }
  }  // end if RTSP
  // #av_dict_set(&opts, "timeout", "10000000", 0); // in microseconds.

  Debug(1, "Calling avformat_open_input for %s", mPath.c_str());

  mFormatContext = avformat_alloc_context();
  // Speed up find_stream_info
  // FIXME can speed up initial analysis but need sensible parameters...
  // mFormatContext->probesize = 32;
  // mFormatContext->max_analyze_duration = 32;
  mFormatContext->interrupt_callback.callback = FfmpegInterruptCallback;
  mFormatContext->interrupt_callback.opaque = this;

  ret = avformat_open_input(&mFormatContext, mPath.c_str(), nullptr, &opts);
  if ( ret != 0 )
#endif
  {
    Error("Unable to open input %s due to: %s", mPath.c_str(),
        av_make_error_string(ret).c_str());
#if !LIBAVFORMAT_VERSION_CHECK(53, 17, 0, 25, 0)
    av_close_input_file(mFormatContext);
#else
    if ( mFormatContext ) {
      avformat_close_input(&mFormatContext);
      mFormatContext = nullptr;
    }
#endif
    av_dict_free(&opts);

    return -1;
  }
  AVDictionaryEntry *e = nullptr;
  while ( (e = av_dict_get(opts, "", e, AV_DICT_IGNORE_SUFFIX)) != nullptr ) {
    Warning("Option %s not recognized by ffmpeg", e->key);
  }
  av_dict_free(&opts);

  Debug(1, "Finding stream info");
#if !LIBAVFORMAT_VERSION_CHECK(53, 6, 0, 6, 0)
  ret = av_find_stream_info(mFormatContext);
#else
  ret = avformat_find_stream_info(mFormatContext, nullptr);
#endif
  if ( ret < 0 ) {
    Error("Unable to find stream info from %s due to: %s",
        mPath.c_str(), av_make_error_string(ret).c_str());
    return -1;
  }

  // Find first video stream present
  // The one we want Might not be the first
  mVideoStreamId = -1;
  mAudioStreamId = -1;
  for ( unsigned int i=0; i < mFormatContext->nb_streams; i++ ) {
    AVStream *stream = mFormatContext->streams[i];
    if ( is_video_stream(stream) ) {
      if ( mVideoStreamId == -1 ) {
        mVideoStreamId = i;
        // if we break, then we won't find the audio stream
        continue;
      } else {
        Debug(2, "Have another video stream.");
      }
    } else if ( is_audio_stream(stream) ) {
      if ( mAudioStreamId == -1 ) {
        mAudioStreamId = i;
      } else {
        Debug(2, "Have another audio stream.");
      }
    }
  }  // end foreach stream

  if ( mVideoStreamId == -1 ) {
    Error("Unable to locate video stream in %s", mPath.c_str());
    return -1;
  }

  Debug(3, "Found video stream at index %d, audio stream at index %d",
      mVideoStreamId, mAudioStreamId);

#if LIBAVCODEC_VERSION_CHECK(57, 64, 0, 64, 0)
  mVideoCodecContext = avcodec_alloc_context3(nullptr);
  avcodec_parameters_to_context(mVideoCodecContext,
  mFormatContext->streams[mVideoStreamId]->codecpar);
  // this isn't copied.
  mVideoCodecContext->time_base =
  mFormatContext->streams[mVideoStreamId]->codec->time_base;
#else
#endif
  //mVideoCodecContext = mFormatContext->streams[mVideoStreamId]->codec;
#ifdef CODEC_FLAG2_FAST
  mVideoCodecContext->flags2 |= CODEC_FLAG2_FAST | CODEC_FLAG_LOW_DELAY;
#endif

  if ( mVideoCodecContext->codec_id == AV_CODEC_ID_H264 ) {
    if ( (mVideoCodec = avcodec_find_decoder_by_name("h264_mmal")) == nullptr ) {
      Debug(1, "Failed to find decoder (h264_mmal)");
    } else {
      Debug(1, "Success finding decoder (h264_mmal)");
    }
  }

  if ( !mVideoCodec ) {
    mVideoCodec = avcodec_find_decoder(mVideoCodecContext->codec_id);
    if ( !mVideoCodec ) {
      // Try and get the codec from the codec context
      Error("Can't find codec for video stream from %s", mPath.c_str());
      return -1;
    }
  }

  zm_dump_stream_format(mFormatContext, mVideoStreamId, 0, 0);

  if ( use_hwaccel && (hwaccel_name != "") ) {
#if HAVE_LIBAVUTIL_HWCONTEXT_H
    // 3.2 doesn't seem to have all the bits in place, so let's require 3.3 and up
  #if LIBAVCODEC_VERSION_CHECK(57, 89, 0, 89, 0)
    // Print out available types
    enum AVHWDeviceType type = AV_HWDEVICE_TYPE_NONE;
    while ( (type = av_hwdevice_iterate_types(type)) != AV_HWDEVICE_TYPE_NONE )
      Debug(1, "%s", av_hwdevice_get_type_name(type));

    const char *hw_name = hwaccel_name.c_str();
    type = av_hwdevice_find_type_by_name(hw_name);
    if ( type == AV_HWDEVICE_TYPE_NONE ) {
      Debug(1, "Device type %s is not supported.", hw_name);
    } else {
      Debug(1, "Found hwdevice %s", av_hwdevice_get_type_name(type));
    }

    #if LIBAVUTIL_VERSION_CHECK(56, 22, 0, 14, 0)
    // Get hw_pix_fmt
    for ( int i = 0;; i++ ) {
      const AVCodecHWConfig *config = avcodec_get_hw_config(mVideoCodec, i);
      if ( !config ) {
        Debug(1, "Decoder %s does not support config %d.",
            mVideoCodec->name, i);
        break;
      }
      if ( (config->methods & AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX)
          && (config->device_type == type)
          ) {
        hw_pix_fmt = config->pix_fmt;
        Debug(1, "Decoder %s does support our type %s.",
            mVideoCodec->name, av_hwdevice_get_type_name(type));
        //break;
      } else {
        Debug(1, "Decoder %s hwConfig doesn't match our type: %s != %s, pix_fmt %s.",
            mVideoCodec->name,
            av_hwdevice_get_type_name(type),
            av_hwdevice_get_type_name(config->device_type),
            av_get_pix_fmt_name(config->pix_fmt)
            );
      }
    }  // end foreach hwconfig
    #else
    hw_pix_fmt = find_fmt_by_hw_type(type);
    #endif
    if ( hw_pix_fmt != AV_PIX_FMT_NONE ) {
      Debug(1, "Selected hw_pix_fmt %d %s",
          hw_pix_fmt, av_get_pix_fmt_name(hw_pix_fmt));

       mVideoCodecContext->hwaccel_flags |= AV_HWACCEL_FLAG_IGNORE_LEVEL;
        //if (!lavc_param->check_hw_profile)
       mVideoCodecContext->hwaccel_flags |= AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH;

      ret = av_hwdevice_ctx_create(&hw_device_ctx, type,
          (hwaccel_device != "" ? hwaccel_device.c_str() : nullptr), nullptr, 0);
      if ( ret < 0 and hwaccel_device != "" ) {
        ret = av_hwdevice_ctx_create(&hw_device_ctx, type, nullptr, nullptr, 0);
      }
      if ( ret < 0 ) {
        Error("Failed to create hwaccel device. %s", av_make_error_string(ret).c_str());
        hw_pix_fmt = AV_PIX_FMT_NONE;
      } else {
        Debug(1, "Created hwdevice for %s", hwaccel_device.c_str());
        mVideoCodecContext->get_format = get_hw_format;
        mVideoCodecContext->hw_device_ctx = av_buffer_ref(hw_device_ctx);

        hwFrame = zm_av_frame_alloc();
      }
    } else {
      Debug(1, "Failed to find suitable hw_pix_fmt.");
    }
  #else
    Debug(1, "AVCodec not new enough for hwaccel");
  #endif
#else
    Warning("HWAccel support not compiled in.");
#endif
  }  // end if hwaccel_name

#if !LIBAVFORMAT_VERSION_CHECK(53, 8, 0, 8, 0)
  ret = avcodec_open(mVideoCodecContext, mVideoCodec);
#else
  ret = avcodec_open2(mVideoCodecContext, mVideoCodec, &opts);
#endif
  e = nullptr;
  while ( (e = av_dict_get(opts, "", e, AV_DICT_IGNORE_SUFFIX)) != nullptr ) {
    Warning("Option %s not recognized by ffmpeg", e->key);
  }
  if ( ret < 0 ) {
    Error("Unable to open codec for video stream from %s", mPath.c_str());
    av_dict_free(&opts);
    return -1;
  }
  zm_dump_codec(mVideoCodecContext);

  Debug(1, hwFrame ? "HWACCEL in use" : "HWACCEL not in use");

  if ( mAudioStreamId >= 0 ) {
    if ( (mAudioCodec = avcodec_find_decoder(
#if LIBAVCODEC_VERSION_CHECK(57, 64, 0, 64, 0)
            mFormatContext->streams[mAudioStreamId]->codecpar->codec_id
#else
            mFormatContext->streams[mAudioStreamId]->codec->codec_id
#endif
            )) == nullptr ) {
      Debug(1, "Can't find codec for audio stream from %s", mPath.c_str());
    } else {
#if LIBAVCODEC_VERSION_CHECK(57, 64, 0, 64, 0)
      mAudioCodecContext = avcodec_alloc_context3(mAudioCodec);
      avcodec_parameters_to_context(
          mAudioCodecContext,
          mFormatContext->streams[mAudioStreamId]->codecpar
          );
#else
      mAudioCodecContext = mFormatContext->streams[mAudioStreamId]->codec;
     // = avcodec_alloc_context3(mAudioCodec);
#endif

      zm_dump_stream_format(mFormatContext, mAudioStreamId, 0, 0);
      // Open the codec
#if !LIBAVFORMAT_VERSION_CHECK(53, 8, 0, 8, 0)
      if ( avcodec_open(mAudioCodecContext, mAudioCodec) < 0 )
#else
      if ( avcodec_open2(mAudioCodecContext, mAudioCodec, nullptr) < 0 )
#endif
      {
        Error("Unable to open codec for audio stream from %s", mPath.c_str());
        return -1;
      } // end if opened
    } // end if found decoder
  }  // end if have audio stream

  if (
      ((unsigned int)mVideoCodecContext->width != width)
      ||
      ((unsigned int)mVideoCodecContext->height != height)
      ) {
    Warning("Monitor dimensions are %dx%d but camera is sending %dx%d",
        width, height, mVideoCodecContext->width, mVideoCodecContext->height);
  }

  mCanCapture = true;

  return 1;
} // int FfmpegCamera::OpenFfmpeg()

int FfmpegCamera::Close() {
  mCanCapture = false;

  if ( mFrame ) {
    av_frame_free(&mFrame);
    mFrame = nullptr;
  }
  if ( mRawFrame ) {
    av_frame_free(&mRawFrame);
    mRawFrame = nullptr;
  }
#if HAVE_LIBAVUTIL_HWCONTEXT_H
  if ( hwFrame ) {
    av_frame_free(&hwFrame);
    hwFrame = nullptr;
  }
#endif

  if ( mVideoCodecContext ) {
    avcodec_close(mVideoCodecContext);
#if LIBAVCODEC_VERSION_CHECK(57, 64, 0, 64, 0)
    avcodec_free_context(&mVideoCodecContext);
#endif
    mVideoCodecContext = nullptr;  // Freed by av_close_input_file
  }
  if ( mAudioCodecContext ) {
    avcodec_close(mAudioCodecContext);
#if LIBAVCODEC_VERSION_CHECK(57, 64, 0, 64, 0)
    avcodec_free_context(&mAudioCodecContext);
#endif
    mAudioCodecContext = nullptr;  // Freed by av_close_input_file
  }

#if HAVE_LIBAVUTIL_HWCONTEXT_H
  if ( hw_device_ctx ) {
    av_buffer_unref(&hw_device_ctx);
  }
#endif

  if ( mFormatContext ) {
#if !LIBAVFORMAT_VERSION_CHECK(53, 17, 0, 25, 0)
    av_close_input_file(mFormatContext);
#else
    avformat_close_input(&mFormatContext);
#endif
    mFormatContext = nullptr;
  }

  return 0;
}  // end FfmpegCamera::Close

int FfmpegCamera::transfer_to_image(
    Image &image,
    AVFrame *output_frame,
    AVFrame *input_frame
    ) {
  uint8_t* image_buffer;  // pointer to buffer in image
  uint8_t* buffer;        // pointer to either image_buffer or frame_buffer

  /* Request a writeable buffer of the target image */
  image_buffer = image.WriteBuffer(width, height, colours, subpixelorder);
  if ( image_buffer == nullptr ) {
    Error("Failed requesting writeable buffer for the captured image.");
    return -1;
  }
  // if image_buffer was allocated then use it.
  buffer = frame_buffer ? frame_buffer : image_buffer;

#if LIBAVUTIL_VERSION_CHECK(54, 6, 0, 6, 0)
  // From what I've read, we should align the linesizes to 32bit so that ffmpeg can use SIMD instructions too.
  int size = av_image_fill_arrays(
      output_frame->data, output_frame->linesize,
      buffer, imagePixFormat, width, height,
      alignment
      );
  if ( size < 0 ) {
    Error("Problem setting up data pointers into image %s",
        av_make_error_string(size).c_str());
  } else {
    Debug(4, "av_image_fill_array %dx%d alignment: %d = %d, buffer size is %d",
        width, height, alignment, size, image.Size());
  }
  Debug(1, "ffmpegcamera: width %d height %d linesize %d colours %d imagesize %d", width, height, linesize, colours, imagesize);
  if ( linesize != (unsigned int)output_frame->linesize[0] ) {
    Error("Bad linesize expected %d got %d", linesize, output_frame->linesize[0]);
  }
#else
  avpicture_fill((AVPicture *)output_frame, buffer,
      imagePixFormat, width, height);
#endif

#if HAVE_LIBSWSCALE
  if ( !mConvertContext ) {
    mConvertContext = sws_getContext(
        input_frame->width,
        input_frame->height,
        (AVPixelFormat)input_frame->format,
        width, height,
        imagePixFormat, SWS_BICUBIC, nullptr,
        nullptr, nullptr);
    if ( mConvertContext == nullptr ) {
      Error("Unable to create conversion context for %s from %s to %s",
          mPath.c_str(),
          av_get_pix_fmt_name((AVPixelFormat)input_frame->format),
          av_get_pix_fmt_name(imagePixFormat)
          );
      return -1;
    }
    Debug(1, "Setup conversion context for %dx%d %s to %dx%d %s",
          input_frame->width, input_frame->height,
          av_get_pix_fmt_name((AVPixelFormat)input_frame->format),
          width, height,
          av_get_pix_fmt_name(imagePixFormat)
        );
  }

  int ret =
      sws_scale(
        mConvertContext, input_frame->data, input_frame->linesize,
        0, mVideoCodecContext->height,
        output_frame->data, output_frame->linesize);
  if ( ret < 0 ) {
    Error("Unable to convert format %u %s linesize %d,%d height %d to format %u %s linesize %d,%d at frame %d codec %u %s lines %d: code: %d",
        input_frame->format, av_get_pix_fmt_name((AVPixelFormat)input_frame->format),
        input_frame->linesize[0], input_frame->linesize[1], mVideoCodecContext->height,
        imagePixFormat,
        av_get_pix_fmt_name(imagePixFormat),
        output_frame->linesize[0], output_frame->linesize[1],
        frameCount,
        mVideoCodecContext->pix_fmt, av_get_pix_fmt_name(mVideoCodecContext->pix_fmt),
        mVideoCodecContext->height,
        ret
        );
    return -1;
  }
  Debug(4, "Able to convert format %u %s linesize %d,%d height %d to format %u %s linesize %d,%d at frame %d codec %u %s %dx%d ",
      input_frame->format, av_get_pix_fmt_name((AVPixelFormat)input_frame->format),
      input_frame->linesize[0], input_frame->linesize[1], mVideoCodecContext->height,
      imagePixFormat,
      av_get_pix_fmt_name(imagePixFormat),
      output_frame->linesize[0], output_frame->linesize[1],
      frameCount,
      mVideoCodecContext->pix_fmt, av_get_pix_fmt_name(mVideoCodecContext->pix_fmt),
      output_frame->width,
      output_frame->height
      );
#else  // HAVE_LIBSWSCALE
  Fatal("You must compile ffmpeg with the --enable-swscale "
      "option to use ffmpeg cameras");
#endif  // HAVE_LIBSWSCALE
  if ( buffer != image_buffer ) {
    Debug(1, "Copying image-buffer to buffer");
    // Have to copy contents of image_buffer to directbuffer.
    // Since linesize isn't the same have to copy line by line
    uint8_t *image_buffer_ptr = image_buffer;
    int row_size = output_frame->width * colours;
    for ( int i = 0; i < output_frame->height; i++ ) {
      memcpy(image_buffer_ptr, buffer, row_size);
      image_buffer_ptr += row_size;
      buffer += output_frame->linesize[0];
    }
  }
  return 0;
}  // end int FfmpegCamera::transfer_to_image

int FfmpegCamera::FfmpegInterruptCallback(void *ctx) {
  // FfmpegCamera* camera = reinterpret_cast<FfmpegCamera*>(ctx);
  // Debug(4, "FfmpegInterruptCallback");
  return zm_terminate;
}

#endif  // HAVE_LIBAVFORMAT