1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-23 12:43:46 +02:00
FFmpeg/libavdevice/decklink_dec.cpp
Aaron Levinson 9e86a61870 avdevice/decklink: remove pthread dependency
Purpose: avdevice/decklink: Removed pthread dependency by replacing
semaphore used in code appropriately.  Doing so makes it easier to
build ffmpeg using Visual C++ on Windows.  This is a contination of
Kyle Schwarz's "avdevice/decklink: Remove pthread dependency" patch
that is available at https://patchwork.ffmpeg.org/patch/2654/ .  This
patch wasn't accepted, and as far as I can tell, there was no
follow-up after it was rejected.

Notes: Used Visual Studio 2015 (with update 3) for this.

Comments:

-- configure: Eliminated pthreads dependency for decklink_indev_deps
   and decklink_outdev_deps and replaced with threads dependency

-- libavdevice/decklink_common.cpp / .h:
a) Eliminated semaphore and replaced with a combination of a mutex,
   condition variable, and a counter (frames_buffer_available_spots).
b) Removed include of pthread.h and semaphore.h and now using
   libavutil/thread.h instead.

-- libavdevice/decklink_dec.cpp: Eliminated include of pthread.h and
   semaphore.h.

-- libavdevice/decklink_enc.cpp:
a) Eliminated include of pthread.h and semaphore.h.
b) Replaced use of semaphore with the equivalent using a combination
   of a mutex, condition variable, and a counter
   (frames_buffer_available_spots).  In theory, libavutil/thread.h and
   the associated code could have been modified instead to add
   cross-platform implementations of the sem_ functions, but an
   inspection of the ffmpeg source base indicates that there are only
   two cases in which semaphores are used (including this one that was
   replaced), so it was deemed to not be worth the effort.

Signed-off-by: Marton Balint <cus@passwd.hu>
2017-04-15 12:26:21 +02:00

659 lines
21 KiB
C++

/*
* Blackmagic DeckLink input
* Copyright (c) 2013-2014 Luca Barbato, Deti Fliegl
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <DeckLinkAPI.h>
extern "C" {
#include "config.h"
#include "libavformat/avformat.h"
#include "libavformat/internal.h"
#include "libavutil/avutil.h"
#include "libavutil/common.h"
#include "libavutil/imgutils.h"
#include "libavutil/time.h"
#include "libavutil/mathematics.h"
#if CONFIG_LIBZVBI
#include <libzvbi.h>
#endif
}
#include "decklink_common.h"
#include "decklink_dec.h"
#if CONFIG_LIBZVBI
static uint8_t calc_parity_and_line_offset(int line)
{
uint8_t ret = (line < 313) << 5;
if (line >= 7 && line <= 22)
ret += line;
if (line >= 320 && line <= 335)
ret += (line - 313);
return ret;
}
int teletext_data_unit_from_vbi_data(int line, uint8_t *src, uint8_t *tgt)
{
vbi_bit_slicer slicer;
vbi_bit_slicer_init(&slicer, 720, 13500000, 6937500, 6937500, 0x00aaaae4, 0xffff, 18, 6, 42 * 8, VBI_MODULATION_NRZ_MSB, VBI_PIXFMT_UYVY);
if (vbi_bit_slice(&slicer, src, tgt + 4) == FALSE)
return -1;
tgt[0] = 0x02; // data_unit_id
tgt[1] = 0x2c; // data_unit_length
tgt[2] = calc_parity_and_line_offset(line); // field_parity, line_offset
tgt[3] = 0xe4; // framing code
return 0;
}
#endif
static void avpacket_queue_init(AVFormatContext *avctx, AVPacketQueue *q)
{
memset(q, 0, sizeof(AVPacketQueue));
pthread_mutex_init(&q->mutex, NULL);
pthread_cond_init(&q->cond, NULL);
q->avctx = avctx;
}
static void avpacket_queue_flush(AVPacketQueue *q)
{
AVPacketList *pkt, *pkt1;
pthread_mutex_lock(&q->mutex);
for (pkt = q->first_pkt; pkt != NULL; pkt = pkt1) {
pkt1 = pkt->next;
av_packet_unref(&pkt->pkt);
av_freep(&pkt);
}
q->last_pkt = NULL;
q->first_pkt = NULL;
q->nb_packets = 0;
q->size = 0;
pthread_mutex_unlock(&q->mutex);
}
static void avpacket_queue_end(AVPacketQueue *q)
{
avpacket_queue_flush(q);
pthread_mutex_destroy(&q->mutex);
pthread_cond_destroy(&q->cond);
}
static unsigned long long avpacket_queue_size(AVPacketQueue *q)
{
unsigned long long size;
pthread_mutex_lock(&q->mutex);
size = q->size;
pthread_mutex_unlock(&q->mutex);
return size;
}
static int avpacket_queue_put(AVPacketQueue *q, AVPacket *pkt)
{
AVPacketList *pkt1;
// Drop Packet if queue size is > 1GB
if (avpacket_queue_size(q) > 1024 * 1024 * 1024 ) {
av_log(q->avctx, AV_LOG_WARNING, "Decklink input buffer overrun!\n");
return -1;
}
/* duplicate the packet */
if (av_dup_packet(pkt) < 0) {
return -1;
}
pkt1 = (AVPacketList *)av_malloc(sizeof(AVPacketList));
if (!pkt1) {
return -1;
}
pkt1->pkt = *pkt;
pkt1->next = NULL;
pthread_mutex_lock(&q->mutex);
if (!q->last_pkt) {
q->first_pkt = pkt1;
} else {
q->last_pkt->next = pkt1;
}
q->last_pkt = pkt1;
q->nb_packets++;
q->size += pkt1->pkt.size + sizeof(*pkt1);
pthread_cond_signal(&q->cond);
pthread_mutex_unlock(&q->mutex);
return 0;
}
static int avpacket_queue_get(AVPacketQueue *q, AVPacket *pkt, int block)
{
AVPacketList *pkt1;
int ret;
pthread_mutex_lock(&q->mutex);
for (;; ) {
pkt1 = q->first_pkt;
if (pkt1) {
q->first_pkt = pkt1->next;
if (!q->first_pkt) {
q->last_pkt = NULL;
}
q->nb_packets--;
q->size -= pkt1->pkt.size + sizeof(*pkt1);
*pkt = pkt1->pkt;
av_free(pkt1);
ret = 1;
break;
} else if (!block) {
ret = 0;
break;
} else {
pthread_cond_wait(&q->cond, &q->mutex);
}
}
pthread_mutex_unlock(&q->mutex);
return ret;
}
class decklink_input_callback : public IDeckLinkInputCallback
{
public:
decklink_input_callback(AVFormatContext *_avctx);
~decklink_input_callback();
virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, LPVOID *ppv) { return E_NOINTERFACE; }
virtual ULONG STDMETHODCALLTYPE AddRef(void);
virtual ULONG STDMETHODCALLTYPE Release(void);
virtual HRESULT STDMETHODCALLTYPE VideoInputFormatChanged(BMDVideoInputFormatChangedEvents, IDeckLinkDisplayMode*, BMDDetectedVideoInputFormatFlags);
virtual HRESULT STDMETHODCALLTYPE VideoInputFrameArrived(IDeckLinkVideoInputFrame*, IDeckLinkAudioInputPacket*);
private:
ULONG m_refCount;
pthread_mutex_t m_mutex;
AVFormatContext *avctx;
decklink_ctx *ctx;
int no_video;
int64_t initial_video_pts;
int64_t initial_audio_pts;
};
decklink_input_callback::decklink_input_callback(AVFormatContext *_avctx) : m_refCount(0)
{
avctx = _avctx;
decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
ctx = (struct decklink_ctx *)cctx->ctx;
no_video = 0;
initial_audio_pts = initial_video_pts = AV_NOPTS_VALUE;
pthread_mutex_init(&m_mutex, NULL);
}
decklink_input_callback::~decklink_input_callback()
{
pthread_mutex_destroy(&m_mutex);
}
ULONG decklink_input_callback::AddRef(void)
{
pthread_mutex_lock(&m_mutex);
m_refCount++;
pthread_mutex_unlock(&m_mutex);
return (ULONG)m_refCount;
}
ULONG decklink_input_callback::Release(void)
{
pthread_mutex_lock(&m_mutex);
m_refCount--;
pthread_mutex_unlock(&m_mutex);
if (m_refCount == 0) {
delete this;
return 0;
}
return (ULONG)m_refCount;
}
static int64_t get_pkt_pts(IDeckLinkVideoInputFrame *videoFrame,
IDeckLinkAudioInputPacket *audioFrame,
int64_t wallclock,
DecklinkPtsSource pts_src,
AVRational time_base, int64_t *initial_pts)
{
int64_t pts = AV_NOPTS_VALUE;
BMDTimeValue bmd_pts;
BMDTimeValue bmd_duration;
HRESULT res = E_INVALIDARG;
switch (pts_src) {
case PTS_SRC_AUDIO:
if (audioFrame)
res = audioFrame->GetPacketTime(&bmd_pts, time_base.den);
break;
case PTS_SRC_VIDEO:
if (videoFrame)
res = videoFrame->GetStreamTime(&bmd_pts, &bmd_duration, time_base.den);
break;
case PTS_SRC_REFERENCE:
if (videoFrame)
res = videoFrame->GetHardwareReferenceTimestamp(time_base.den, &bmd_pts, &bmd_duration);
break;
case PTS_SRC_WALLCLOCK:
pts = av_rescale_q(wallclock, AV_TIME_BASE_Q, time_base);
break;
}
if (res == S_OK)
pts = bmd_pts / time_base.num;
if (pts != AV_NOPTS_VALUE && *initial_pts == AV_NOPTS_VALUE)
*initial_pts = pts;
if (*initial_pts != AV_NOPTS_VALUE)
pts -= *initial_pts;
return pts;
}
HRESULT decklink_input_callback::VideoInputFrameArrived(
IDeckLinkVideoInputFrame *videoFrame, IDeckLinkAudioInputPacket *audioFrame)
{
void *frameBytes;
void *audioFrameBytes;
BMDTimeValue frameTime;
BMDTimeValue frameDuration;
int64_t wallclock = 0;
ctx->frameCount++;
if (ctx->audio_pts_source == PTS_SRC_WALLCLOCK || ctx->video_pts_source == PTS_SRC_WALLCLOCK)
wallclock = av_gettime_relative();
// Handle Video Frame
if (videoFrame) {
AVPacket pkt;
av_init_packet(&pkt);
if (ctx->frameCount % 25 == 0) {
unsigned long long qsize = avpacket_queue_size(&ctx->queue);
av_log(avctx, AV_LOG_DEBUG,
"Frame received (#%lu) - Valid (%liB) - QSize %fMB\n",
ctx->frameCount,
videoFrame->GetRowBytes() * videoFrame->GetHeight(),
(double)qsize / 1024 / 1024);
}
videoFrame->GetBytes(&frameBytes);
videoFrame->GetStreamTime(&frameTime, &frameDuration,
ctx->video_st->time_base.den);
if (videoFrame->GetFlags() & bmdFrameHasNoInputSource) {
if (ctx->draw_bars && videoFrame->GetPixelFormat() == bmdFormat8BitYUV) {
unsigned bars[8] = {
0xEA80EA80, 0xD292D210, 0xA910A9A5, 0x90229035,
0x6ADD6ACA, 0x51EF515A, 0x286D28EF, 0x10801080 };
int width = videoFrame->GetWidth();
int height = videoFrame->GetHeight();
unsigned *p = (unsigned *)frameBytes;
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x += 2)
*p++ = bars[(x * 8) / width];
}
}
if (!no_video) {
av_log(avctx, AV_LOG_WARNING, "Frame received (#%lu) - No input signal detected "
"- Frames dropped %u\n", ctx->frameCount, ++ctx->dropped);
}
no_video = 1;
} else {
if (no_video) {
av_log(avctx, AV_LOG_WARNING, "Frame received (#%lu) - Input returned "
"- Frames dropped %u\n", ctx->frameCount, ++ctx->dropped);
}
no_video = 0;
}
pkt.pts = get_pkt_pts(videoFrame, audioFrame, wallclock, ctx->video_pts_source, ctx->video_st->time_base, &initial_video_pts);
pkt.dts = pkt.pts;
pkt.duration = frameDuration;
//To be made sure it still applies
pkt.flags |= AV_PKT_FLAG_KEY;
pkt.stream_index = ctx->video_st->index;
pkt.data = (uint8_t *)frameBytes;
pkt.size = videoFrame->GetRowBytes() *
videoFrame->GetHeight();
//fprintf(stderr,"Video Frame size %d ts %d\n", pkt.size, pkt.pts);
#if CONFIG_LIBZVBI
if (!no_video && ctx->teletext_lines && videoFrame->GetPixelFormat() == bmdFormat8BitYUV && videoFrame->GetWidth() == 720) {
IDeckLinkVideoFrameAncillary *vanc;
AVPacket txt_pkt;
uint8_t txt_buf0[1611]; // max 35 * 46 bytes decoded teletext lines + 1 byte data_identifier
uint8_t *txt_buf = txt_buf0;
if (videoFrame->GetAncillaryData(&vanc) == S_OK) {
int i;
int64_t line_mask = 1;
txt_buf[0] = 0x10; // data_identifier - EBU_data
txt_buf++;
for (i = 6; i < 336; i++, line_mask <<= 1) {
uint8_t *buf;
if ((ctx->teletext_lines & line_mask) && vanc->GetBufferForVerticalBlankingLine(i, (void**)&buf) == S_OK) {
if (teletext_data_unit_from_vbi_data(i, buf, txt_buf) >= 0)
txt_buf += 46;
}
if (i == 22)
i = 317;
}
vanc->Release();
if (txt_buf - txt_buf0 > 1) {
int stuffing_units = (4 - ((45 + txt_buf - txt_buf0) / 46) % 4) % 4;
while (stuffing_units--) {
memset(txt_buf, 0xff, 46);
txt_buf[1] = 0x2c; // data_unit_length
txt_buf += 46;
}
av_init_packet(&txt_pkt);
txt_pkt.pts = pkt.pts;
txt_pkt.dts = pkt.dts;
txt_pkt.stream_index = ctx->teletext_st->index;
txt_pkt.data = txt_buf0;
txt_pkt.size = txt_buf - txt_buf0;
if (avpacket_queue_put(&ctx->queue, &txt_pkt) < 0) {
++ctx->dropped;
}
}
}
}
#endif
if (avpacket_queue_put(&ctx->queue, &pkt) < 0) {
++ctx->dropped;
}
}
// Handle Audio Frame
if (audioFrame) {
AVPacket pkt;
BMDTimeValue audio_pts;
av_init_packet(&pkt);
//hack among hacks
pkt.size = audioFrame->GetSampleFrameCount() * ctx->audio_st->codecpar->channels * (16 / 8);
audioFrame->GetBytes(&audioFrameBytes);
audioFrame->GetPacketTime(&audio_pts, ctx->audio_st->time_base.den);
pkt.pts = get_pkt_pts(videoFrame, audioFrame, wallclock, ctx->audio_pts_source, ctx->audio_st->time_base, &initial_audio_pts);
pkt.dts = pkt.pts;
//fprintf(stderr,"Audio Frame size %d ts %d\n", pkt.size, pkt.pts);
pkt.flags |= AV_PKT_FLAG_KEY;
pkt.stream_index = ctx->audio_st->index;
pkt.data = (uint8_t *)audioFrameBytes;
if (avpacket_queue_put(&ctx->queue, &pkt) < 0) {
++ctx->dropped;
}
}
return S_OK;
}
HRESULT decklink_input_callback::VideoInputFormatChanged(
BMDVideoInputFormatChangedEvents events, IDeckLinkDisplayMode *mode,
BMDDetectedVideoInputFormatFlags)
{
return S_OK;
}
static HRESULT decklink_start_input(AVFormatContext *avctx)
{
struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
struct decklink_ctx *ctx = (struct decklink_ctx *)cctx->ctx;
ctx->input_callback = new decklink_input_callback(avctx);
ctx->dli->SetCallback(ctx->input_callback);
return ctx->dli->StartStreams();
}
extern "C" {
av_cold int ff_decklink_read_close(AVFormatContext *avctx)
{
struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
struct decklink_ctx *ctx = (struct decklink_ctx *)cctx->ctx;
if (ctx->capture_started) {
ctx->dli->StopStreams();
ctx->dli->DisableVideoInput();
ctx->dli->DisableAudioInput();
}
ff_decklink_cleanup(avctx);
avpacket_queue_end(&ctx->queue);
av_freep(&cctx->ctx);
return 0;
}
av_cold int ff_decklink_read_header(AVFormatContext *avctx)
{
struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
struct decklink_ctx *ctx;
AVStream *st;
HRESULT result;
char fname[1024];
char *tmp;
int mode_num = 0;
int ret;
ctx = (struct decklink_ctx *) av_mallocz(sizeof(struct decklink_ctx));
if (!ctx)
return AVERROR(ENOMEM);
ctx->list_devices = cctx->list_devices;
ctx->list_formats = cctx->list_formats;
ctx->teletext_lines = cctx->teletext_lines;
ctx->preroll = cctx->preroll;
ctx->duplex_mode = cctx->duplex_mode;
if (cctx->video_input > 0 && (unsigned int)cctx->video_input < FF_ARRAY_ELEMS(decklink_video_connection_map))
ctx->video_input = decklink_video_connection_map[cctx->video_input];
if (cctx->audio_input > 0 && (unsigned int)cctx->audio_input < FF_ARRAY_ELEMS(decklink_audio_connection_map))
ctx->audio_input = decklink_audio_connection_map[cctx->audio_input];
ctx->audio_pts_source = cctx->audio_pts_source;
ctx->video_pts_source = cctx->video_pts_source;
ctx->draw_bars = cctx->draw_bars;
cctx->ctx = ctx;
#if !CONFIG_LIBZVBI
if (ctx->teletext_lines) {
av_log(avctx, AV_LOG_ERROR, "Libzvbi support is needed for capturing teletext, please recompile FFmpeg.\n");
return AVERROR(ENOSYS);
}
#endif
/* Check audio channel option for valid values: 2, 8 or 16 */
switch (cctx->audio_channels) {
case 2:
case 8:
case 16:
break;
default:
av_log(avctx, AV_LOG_ERROR, "Value of channels option must be one of 2, 8 or 16\n");
return AVERROR(EINVAL);
}
/* List available devices. */
if (ctx->list_devices) {
ff_decklink_list_devices(avctx);
return AVERROR_EXIT;
}
strcpy (fname, avctx->filename);
tmp=strchr (fname, '@');
if (tmp != NULL) {
av_log(avctx, AV_LOG_WARNING, "The @mode syntax is deprecated and will be removed. Please use the -format_code option.\n");
mode_num = atoi (tmp+1);
*tmp = 0;
}
ret = ff_decklink_init_device(avctx, fname);
if (ret < 0)
return ret;
/* Get input device. */
if (ctx->dl->QueryInterface(IID_IDeckLinkInput, (void **) &ctx->dli) != S_OK) {
av_log(avctx, AV_LOG_ERROR, "Could not open input device from '%s'\n",
avctx->filename);
ret = AVERROR(EIO);
goto error;
}
/* List supported formats. */
if (ctx->list_formats) {
ff_decklink_list_formats(avctx, DIRECTION_IN);
ret = AVERROR_EXIT;
goto error;
}
if (mode_num > 0 || cctx->format_code) {
if (ff_decklink_set_format(avctx, DIRECTION_IN, mode_num) < 0) {
av_log(avctx, AV_LOG_ERROR, "Could not set mode number %d or format code %s for %s\n",
mode_num, (cctx->format_code) ? cctx->format_code : "(unset)", fname);
ret = AVERROR(EIO);
goto error;
}
}
/* Setup streams. */
st = avformat_new_stream(avctx, NULL);
if (!st) {
av_log(avctx, AV_LOG_ERROR, "Cannot add stream\n");
ret = AVERROR(ENOMEM);
goto error;
}
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE;
st->codecpar->sample_rate = bmdAudioSampleRate48kHz;
st->codecpar->channels = cctx->audio_channels;
avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
ctx->audio_st=st;
st = avformat_new_stream(avctx, NULL);
if (!st) {
av_log(avctx, AV_LOG_ERROR, "Cannot add stream\n");
ret = AVERROR(ENOMEM);
goto error;
}
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->width = ctx->bmd_width;
st->codecpar->height = ctx->bmd_height;
st->time_base.den = ctx->bmd_tb_den;
st->time_base.num = ctx->bmd_tb_num;
av_stream_set_r_frame_rate(st, av_make_q(st->time_base.den, st->time_base.num));
if (cctx->v210) {
st->codecpar->codec_id = AV_CODEC_ID_V210;
st->codecpar->codec_tag = MKTAG('V', '2', '1', '0');
st->codecpar->bit_rate = av_rescale(ctx->bmd_width * ctx->bmd_height * 64, st->time_base.den, st->time_base.num * 3);
} else {
st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
st->codecpar->format = AV_PIX_FMT_UYVY422;
st->codecpar->codec_tag = MKTAG('U', 'Y', 'V', 'Y');
st->codecpar->bit_rate = av_rescale(ctx->bmd_width * ctx->bmd_height * 16, st->time_base.den, st->time_base.num);
}
avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
ctx->video_st=st;
if (ctx->teletext_lines) {
st = avformat_new_stream(avctx, NULL);
if (!st) {
av_log(avctx, AV_LOG_ERROR, "Cannot add stream\n");
ret = AVERROR(ENOMEM);
goto error;
}
st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->time_base.den = ctx->bmd_tb_den;
st->time_base.num = ctx->bmd_tb_num;
st->codecpar->codec_id = AV_CODEC_ID_DVB_TELETEXT;
avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
ctx->teletext_st = st;
}
av_log(avctx, AV_LOG_VERBOSE, "Using %d input audio channels\n", ctx->audio_st->codecpar->channels);
result = ctx->dli->EnableAudioInput(bmdAudioSampleRate48kHz, bmdAudioSampleType16bitInteger, ctx->audio_st->codecpar->channels);
if (result != S_OK) {
av_log(avctx, AV_LOG_ERROR, "Cannot enable audio input\n");
ret = AVERROR(EIO);
goto error;
}
result = ctx->dli->EnableVideoInput(ctx->bmd_mode,
cctx->v210 ? bmdFormat10BitYUV : bmdFormat8BitYUV,
bmdVideoInputFlagDefault);
if (result != S_OK) {
av_log(avctx, AV_LOG_ERROR, "Cannot enable video input\n");
ret = AVERROR(EIO);
goto error;
}
avpacket_queue_init (avctx, &ctx->queue);
if (decklink_start_input (avctx) != S_OK) {
av_log(avctx, AV_LOG_ERROR, "Cannot start input stream\n");
ret = AVERROR(EIO);
goto error;
}
return 0;
error:
ff_decklink_cleanup(avctx);
return ret;
}
int ff_decklink_read_packet(AVFormatContext *avctx, AVPacket *pkt)
{
struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
struct decklink_ctx *ctx = (struct decklink_ctx *)cctx->ctx;
AVFrame *frame = ctx->video_st->codec->coded_frame;
avpacket_queue_get(&ctx->queue, pkt, 1);
if (frame && (ctx->bmd_field_dominance == bmdUpperFieldFirst || ctx->bmd_field_dominance == bmdLowerFieldFirst)) {
frame->interlaced_frame = 1;
if (ctx->bmd_field_dominance == bmdUpperFieldFirst) {
frame->top_field_first = 1;
}
}
return 0;
}
} /* extern "C" */