encoding.c

 
#include <winpr/assert.h>
#include <winpr/winpr.h>
 
#include "camera.h"
 
#define TAG CHANNELS_TAG("rdpecam-video.client")
 
#if defined(WITH_INPUT_FORMAT_H264)
/*
 * demux a H264 frame from a MJPG container
 * args:
 *    srcData - pointer to buffer with h264 muxed in MJPG container
 *    srcSize - buff size
 *    h264_data - pointer to h264 data
 *    h264_max_size - maximum size allowed by h264_data buffer
 *
 * Credits:
 *    guvcview    http://guvcview.sourceforge.net
 *    Paulo Assis <pj.assis@gmail.com>
 *
 * see Figure 5 Payload Size in USB_Video_Payload_H 264_1 0.pdf
 * for format details
 *
 * @return: data size and copies demuxed data to h264 buffer
 */
static size_t demux_uvcH264(const BYTE* srcData, size_t srcSize, BYTE* h264_data,
                            size_t h264_max_size)
{
  WINPR_ASSERT(h264_data);
  WINPR_ASSERT(srcData);
 
  if (srcSize < 30)
  {
    WLog_ERR(TAG, "Expected srcSize >= 30, got %" PRIuz, srcSize);
    return 0;
  }
  const uint8_t* spl = NULL;
  uint8_t* ph264 = h264_data;
 
  /* search for 1st APP4 marker
   * (30 = 2 APP4 marker + 2 length + 22 header + 4 payload size)
   */
  for (const uint8_t* sp = srcData; sp < srcData + srcSize - 30; sp++)
  {
    if (sp[0] == 0xFF && sp[1] == 0xE4)
    {
      spl = sp + 2; /* exclude APP4 marker */
      break;
    }
  }
 
  if (spl == NULL)
  {
    WLog_ERR(TAG, "Expected 1st APP4 marker but none found");
    return 0;
  }
 
  if (spl > srcData + srcSize - 4)
  {
    WLog_ERR(TAG, "Payload + Header size bigger than srcData buffer");
    return 0;
  }
 
  /* 1st segment length in big endian
   * includes payload size + header + 6 bytes (2 length + 4 payload size)
   */
  uint16_t length = (uint16_t)(spl[0] << 8) & UINT16_MAX;
  length |= (uint16_t)spl[1];
 
  spl += 2; /* header */
  /* header length in little endian at offset 2 */
  uint16_t header_length = (uint16_t)spl[2];
  header_length |= (uint16_t)spl[3] << 8;
 
  spl += header_length;
  if (spl > srcData + srcSize)
  {
    WLog_ERR(TAG, "Header size bigger than srcData buffer");
    return 0;
  }
 
  /* payload size in little endian */
  uint32_t payload_size = (uint32_t)spl[0] << 0;
  payload_size |= (uint32_t)spl[1] << 8;
  payload_size |= (uint32_t)spl[2] << 16;
  payload_size |= (uint32_t)spl[3] << 24;
 
  if (payload_size > h264_max_size)
  {
    WLog_ERR(TAG, "Payload size bigger than h264_data buffer");
    return 0;
  }
 
  spl += 4;                                /* payload start */
  const uint8_t* epl = spl + payload_size; /* payload end */
 
  if (epl > srcData + srcSize)
  {
    WLog_ERR(TAG, "Payload size bigger than srcData buffer");
    return 0;
  }
 
  length -= header_length + 6;
 
  /* copy 1st segment to h264 buffer */
  memcpy(ph264, spl, length);
  ph264 += length;
  spl += length;
 
  /* copy other segments */
  while (epl > spl + 4)
  {
    if (spl[0] != 0xFF || spl[1] != 0xE4)
    {
      WLog_ERR(TAG, "Expected 2nd+ APP4 marker but none found");
      const intptr_t diff = ph264 - h264_data;
      return WINPR_ASSERTING_INT_CAST(size_t, diff);
    }
 
    /* 2nd+ segment length in big endian */
    length = (uint16_t)(spl[2] << 8) & UINT16_MAX;
    length |= (uint16_t)spl[3];
    if (length < 2)
    {
      WLog_ERR(TAG, "Expected 2nd+ APP4 length >= 2 but have %" PRIu16, length);
      return 0;
    }
 
    length -= 2;
    spl += 4; /* APP4 marker + length */
 
    /* copy segment to h264 buffer */
    memcpy(ph264, spl, length);
    ph264 += length;
    spl += length;
  }
 
  const intptr_t diff = ph264 - h264_data;
  return WINPR_ASSERTING_INT_CAST(size_t, diff);
}
#endif
 
UINT32 h264_get_max_bitrate(UINT32 height)
{
  static struct Bitrates
  {
    UINT32 height;
    UINT32 bitrate; /* kbps */
 
  } bitrates[] = {
    /* source: https://livekit.io/webrtc/bitrate-guide (webcam streaming)
     *
     * sorted by height in descending order
     */
    { 1080, 2700 }, { 720, 1250 }, { 480, 700 }, { 360, 400 },
    { 240, 170 },   { 180, 140 },  { 0, 100 },
  };
  const size_t nBitrates = ARRAYSIZE(bitrates);
 
  for (size_t i = 0; i < nBitrates; i++)
  {
    if (height >= bitrates[i].height)
    {
      UINT32 bitrate = bitrates[i].bitrate;
      WLog_DBG(TAG, "Setting h264 max bitrate: %u kbps", bitrate);
      return bitrate * 1000;
    }
  }
 
  WINPR_ASSERT(FALSE);
  return 0;
}
 
static enum AVPixelFormat ecamToAVPixFormat(CAM_MEDIA_FORMAT ecamFormat)
{
  switch (ecamFormat)
  {
    case CAM_MEDIA_FORMAT_YUY2:
      return AV_PIX_FMT_YUYV422;
    case CAM_MEDIA_FORMAT_NV12:
      return AV_PIX_FMT_NV12;
    case CAM_MEDIA_FORMAT_I420:
      return AV_PIX_FMT_YUV420P;
    case CAM_MEDIA_FORMAT_RGB24:
      return AV_PIX_FMT_RGB24;
    case CAM_MEDIA_FORMAT_RGB32:
      return AV_PIX_FMT_RGB32;
    default:
      WLog_ERR(TAG, "Unsupported ecamFormat %u", ecamFormat);
      return AV_PIX_FMT_NONE;
  }
}
 
static void ecam_sws_free(CameraDeviceStream* stream)
{
  if (stream->sws)
  {
    sws_freeContext(stream->sws);
    stream->sws = NULL;
  }
}
 
static BOOL ecam_sws_valid(const CameraDeviceStream* stream)
{
  if (!stream->sws)
    return FALSE;
  if (stream->swsWidth != stream->currMediaType.Width)
    return FALSE;
  if (stream->swsHeight != stream->currMediaType.Height)
    return FALSE;
  if (stream->currMediaType.Width > INT32_MAX)
    return FALSE;
  if (stream->currMediaType.Height > INT32_MAX)
    return FALSE;
  return TRUE;
}
 
static BOOL ecam_init_sws_context(CameraDeviceStream* stream, enum AVPixelFormat pixFormat)
{
  WINPR_ASSERT(stream);
 
  if (stream->currMediaType.Width > INT32_MAX)
    return FALSE;
  if (stream->currMediaType.Height > INT32_MAX)
    return FALSE;
 
  if (ecam_sws_valid(stream))
    return TRUE;
 
  ecam_sws_free(stream);
 
  /* replacing deprecated JPEG formats, still produced by decoder */
  switch (pixFormat)
  {
    case AV_PIX_FMT_YUVJ411P:
      pixFormat = AV_PIX_FMT_YUV411P;
      break;
 
    case AV_PIX_FMT_YUVJ420P:
      pixFormat = AV_PIX_FMT_YUV420P;
      break;
 
    case AV_PIX_FMT_YUVJ422P:
      pixFormat = AV_PIX_FMT_YUV422P;
      break;
 
    case AV_PIX_FMT_YUVJ440P:
      pixFormat = AV_PIX_FMT_YUV440P;
      break;
 
    case AV_PIX_FMT_YUVJ444P:
      pixFormat = AV_PIX_FMT_YUV444P;
      break;
 
    default:
      break;
  }
 
  stream->swsWidth = stream->currMediaType.Width;
  stream->swsHeight = stream->currMediaType.Height;
  const int width = WINPR_ASSERTING_INT_CAST(int, stream->currMediaType.Width);
  const int height = WINPR_ASSERTING_INT_CAST(int, stream->currMediaType.Height);
 
  const enum AVPixelFormat outPixFormat =
      h264_context_get_option(stream->h264, H264_CONTEXT_OPTION_HW_ACCEL) ? AV_PIX_FMT_NV12
                                                                          : AV_PIX_FMT_YUV420P;
 
  stream->sws =
      sws_getContext(width, height, pixFormat, width, height, outPixFormat, 0, NULL, NULL, NULL);
  if (!stream->sws)
  {
    WLog_ERR(TAG, "sws_getContext failed");
    return FALSE;
  }
 
  return TRUE;
}
 
static BOOL ecam_encoder_compress_h264(CameraDeviceStream* stream, const BYTE* srcData,
                                       size_t srcSize, BYTE** ppDstData, size_t* pDstSize)
{
  UINT32 dstSize = 0;
  BYTE* srcSlice[4] = { 0 };
  int srcLineSizes[4] = { 0 };
  BYTE* yuvData[3] = { 0 };
  UINT32 yuvLineSizes[3] = { 0 };
  prim_size_t size = { stream->currMediaType.Width, stream->currMediaType.Height };
  CAM_MEDIA_FORMAT inputFormat = streamInputFormat(stream);
  enum AVPixelFormat pixFormat = AV_PIX_FMT_NONE;
 
#if defined(WITH_INPUT_FORMAT_H264)
  if (inputFormat == CAM_MEDIA_FORMAT_MJPG_H264)
  {
    const size_t rc =
        demux_uvcH264(srcData, srcSize, stream->h264Frame, stream->h264FrameMaxSize);
    dstSize = WINPR_ASSERTING_INT_CAST(uint32_t, rc);
    *ppDstData = stream->h264Frame;
    *pDstSize = dstSize;
    return dstSize > 0;
  }
  else
#endif
 
#if defined(WITH_INPUT_FORMAT_MJPG)
      if (inputFormat == CAM_MEDIA_FORMAT_MJPG)
  {
    stream->avInputPkt->data = WINPR_CAST_CONST_PTR_AWAY(srcData, uint8_t*);
    WINPR_ASSERT(srcSize <= INT32_MAX);
    stream->avInputPkt->size = (int)srcSize;
 
    if (avcodec_send_packet(stream->avContext, stream->avInputPkt) < 0)
    {
      WLog_ERR(TAG, "avcodec_send_packet failed");
      return FALSE;
    }
 
    if (avcodec_receive_frame(stream->avContext, stream->avOutFrame) < 0)
    {
      WLog_ERR(TAG, "avcodec_receive_frame failed");
      return FALSE;
    }
 
    for (size_t i = 0; i < 4; i++)
    {
      srcSlice[i] = stream->avOutFrame->data[i];
      srcLineSizes[i] = stream->avOutFrame->linesize[i];
    }
 
    /* get pixFormat produced by MJPEG decoder */
    pixFormat = stream->avContext->pix_fmt;
  }
  else
#endif
  {
    pixFormat = ecamToAVPixFormat(inputFormat);
 
    if (av_image_fill_linesizes(srcLineSizes, pixFormat, (int)size.width) < 0)
    {
      WLog_ERR(TAG, "av_image_fill_linesizes failed");
      return FALSE;
    }
 
    if (av_image_fill_pointers(srcSlice, pixFormat, (int)size.height,
                               WINPR_CAST_CONST_PTR_AWAY(srcData, BYTE*), srcLineSizes) < 0)
    {
      WLog_ERR(TAG, "av_image_fill_pointers failed");
      return FALSE;
    }
  }
 
  /* get buffers for YUV420P or NV12 */
  if (h264_get_yuv_buffer(stream->h264, 0, size.width, size.height, yuvData, yuvLineSizes) < 0)
    return FALSE;
 
  /* convert from source format to YUV420P or NV12 */
  if (!ecam_init_sws_context(stream, pixFormat))
    return FALSE;
 
  const BYTE* cSrcSlice[4] = { srcSlice[0], srcSlice[1], srcSlice[2], srcSlice[3] };
  if (sws_scale(stream->sws, cSrcSlice, srcLineSizes, 0, (int)size.height, yuvData,
                (int*)yuvLineSizes) <= 0)
    return FALSE;
 
  /* encode from YUV420P or NV12 to H264 */
  if (h264_compress(stream->h264, ppDstData, &dstSize) < 0)
    return FALSE;
 
  *pDstSize = dstSize;
 
  return TRUE;
}
 
static void ecam_encoder_context_free_h264(CameraDeviceStream* stream)
{
  WINPR_ASSERT(stream);
 
  ecam_sws_free(stream);
 
#if defined(WITH_INPUT_FORMAT_MJPG)
  if (stream->avOutFrame)
    av_frame_free(&stream->avOutFrame); /* sets to NULL */
 
  if (stream->avInputPkt)
  {
    stream->avInputPkt->data = NULL;
    stream->avInputPkt->size = 0;
    av_packet_free(&stream->avInputPkt); /* sets to NULL */
  }
 
  if (stream->avContext)
    avcodec_free_context(&stream->avContext); /* sets to NULL */
#endif
 
#if defined(WITH_INPUT_FORMAT_H264)
  if (stream->h264Frame)
  {
    free(stream->h264Frame);
    stream->h264Frame = NULL;
  }
#endif
 
  if (stream->h264)
  {
    h264_context_free(stream->h264);
    stream->h264 = NULL;
  }
}
 
#if defined(WITH_INPUT_FORMAT_MJPG)
static BOOL ecam_init_mjpeg_decoder(CameraDeviceStream* stream)
{
  WINPR_ASSERT(stream);
 
  const AVCodec* avcodec = avcodec_find_decoder(AV_CODEC_ID_MJPEG);
  if (!avcodec)
  {
    WLog_ERR(TAG, "avcodec_find_decoder failed to find MJPEG codec");
    return FALSE;
  }
 
  stream->avContext = avcodec_alloc_context3(avcodec);
  if (!stream->avContext)
  {
    WLog_ERR(TAG, "avcodec_alloc_context3 failed");
    return FALSE;
  }
 
  stream->avContext->width = WINPR_ASSERTING_INT_CAST(int, stream->currMediaType.Width);
  stream->avContext->height = WINPR_ASSERTING_INT_CAST(int, stream->currMediaType.Height);
 
  /* AV_EF_EXPLODE flag is to abort decoding on minor error detection,
   * return error, so we can skip corrupted frames, if any */
  stream->avContext->err_recognition |= AV_EF_EXPLODE;
 
  if (avcodec_open2(stream->avContext, avcodec, NULL) < 0)
  {
    WLog_ERR(TAG, "avcodec_open2 failed");
    return FALSE;
  }
 
  stream->avInputPkt = av_packet_alloc();
  if (!stream->avInputPkt)
  {
    WLog_ERR(TAG, "av_packet_alloc failed");
    return FALSE;
  }
 
  stream->avOutFrame = av_frame_alloc();
  if (!stream->avOutFrame)
  {
    WLog_ERR(TAG, "av_frame_alloc failed");
    return FALSE;
  }
 
  return TRUE;
}
#endif
 
static BOOL ecam_encoder_context_init_h264(CameraDeviceStream* stream)
{
  WINPR_ASSERT(stream);
 
#if defined(WITH_INPUT_FORMAT_H264)
  if (streamInputFormat(stream) == CAM_MEDIA_FORMAT_MJPG_H264)
  {
    stream->h264FrameMaxSize = 1ULL * stream->currMediaType.Width *
                               stream->currMediaType.Height; /* 1 byte per pixel */
    stream->h264Frame = (BYTE*)calloc(stream->h264FrameMaxSize, sizeof(BYTE));
    return TRUE; /* encoder not needed */
  }
#endif
 
  if (!stream->h264)
    stream->h264 = h264_context_new(TRUE);
 
  if (!stream->h264)
  {
    WLog_ERR(TAG, "h264_context_new failed");
    return FALSE;
  }
 
  if (!h264_context_set_option(stream->h264, H264_CONTEXT_OPTION_USAGETYPE,
                               H264_CAMERA_VIDEO_REAL_TIME))
    goto fail;
 
  if (!h264_context_set_option(stream->h264, H264_CONTEXT_OPTION_FRAMERATE,
                               stream->currMediaType.FrameRateNumerator /
                                   stream->currMediaType.FrameRateDenominator))
    goto fail;
 
  if (!h264_context_set_option(stream->h264, H264_CONTEXT_OPTION_BITRATE,
                               h264_get_max_bitrate(stream->currMediaType.Height)))
    goto fail;
 
  /* Using CQP mode for rate control. It produces more comparable quality
   * between VAAPI and software encoding than VBR mode
   */
  if (!h264_context_set_option(stream->h264, H264_CONTEXT_OPTION_RATECONTROL,
                               H264_RATECONTROL_CQP))
    goto fail;
 
  /* Using 26 as CQP value. Lower values will produce better quality but
   * higher bitrate; higher values - lower bitrate but degraded quality
   */
  if (!h264_context_set_option(stream->h264, H264_CONTEXT_OPTION_QP, 26))
    goto fail;
 
  /* Requesting hardware acceleration before calling h264_context_reset */
  if (!h264_context_set_option(stream->h264, H264_CONTEXT_OPTION_HW_ACCEL, TRUE))
    goto fail;
 
  if (!h264_context_reset(stream->h264, stream->currMediaType.Width,
                          stream->currMediaType.Height))
  {
    WLog_ERR(TAG, "h264_context_reset failed");
    goto fail;
  }
 
#if defined(WITH_INPUT_FORMAT_MJPG)
  if (streamInputFormat(stream) == CAM_MEDIA_FORMAT_MJPG && !ecam_init_mjpeg_decoder(stream))
    goto fail;
#endif
 
  return TRUE;
 
fail:
  ecam_encoder_context_free_h264(stream);
  return FALSE;
}
 
BOOL ecam_encoder_context_init(CameraDeviceStream* stream)
{
  CAM_MEDIA_FORMAT format = streamOutputFormat(stream);
 
  switch (format)
  {
    case CAM_MEDIA_FORMAT_H264:
      return ecam_encoder_context_init_h264(stream);
 
    default:
      WLog_ERR(TAG, "Unsupported output format %u", format);
      return FALSE;
  }
}
 
BOOL ecam_encoder_context_free(CameraDeviceStream* stream)
{
  CAM_MEDIA_FORMAT format = streamOutputFormat(stream);
  switch (format)
  {
    case CAM_MEDIA_FORMAT_H264:
      ecam_encoder_context_free_h264(stream);
      break;
 
    default:
      return FALSE;
  }
  return TRUE;
}
 
BOOL ecam_encoder_compress(CameraDeviceStream* stream, const BYTE* srcData, size_t srcSize,
                           BYTE** ppDstData, size_t* pDstSize)
{
  CAM_MEDIA_FORMAT format = streamOutputFormat(stream);
  switch (format)
  {
    case CAM_MEDIA_FORMAT_H264:
      return ecam_encoder_compress_h264(stream, srcData, srcSize, ppDstData, pDstSize);
    default:
      WLog_ERR(TAG, "Unsupported output format %u", format);
      return FALSE;
  }
}