[FFmpeg-devel] [PATCH RFC] libavdevice/decklink: Add support for EIA-708 output over SDI

Marton Balint cus at passwd.hu
Wed Oct 25 21:23:07 EEST 2017


On Fri, 6 Oct 2017, Devin Heitmueller wrote:

> From: Devin Heitmueller <dheitmueller at kernellabs.com>
>
> Hook in libklvanc and use it for output of EIA-708 captions over
> SDI.  The bulk of this patch is just general support for ancillary
> data for the Decklink SDI module - the real work for construction
> of the EIA-708 CDP and VANC line construction is done by libklvanc.
>
> Libklvanc can be found at: https://github.com/stoth68000/libklvanc

Sorry for the delay, I had little time lately. In general I think it is OK 
to put VANC functionality into a library, but libklvanc does not seem like 
a very mature one, it has some pretty generic function names without 
namespacing, e.g. "generate_vanc_line". Or it is using simple printf for 
the dumper functions. You plan to work on these kind of issues to make 
it more like a "stable" generic library?

>
> Signed-off-by: Devin Heitmueller <dheitmueller at ltnglobal.com>
> ---
> configure                     |   3 ++
> libavcodec/v210enc.c          |   8 +++
> libavdevice/decklink_common.h |   1 +
> libavdevice/decklink_enc.cpp  | 113 +++++++++++++++++++++++++++++++++++++++---
> 4 files changed, 119 insertions(+), 6 deletions(-)
>
> diff --git a/configure b/configure
> index 391c141e7a..18647896b1 100755
> --- a/configure
> +++ b/configure
> @@ -238,6 +238,7 @@ External library support:
>   --enable-libgsm          enable GSM de/encoding via libgsm [no]
>   --enable-libiec61883     enable iec61883 via libiec61883 [no]
>   --enable-libilbc         enable iLBC de/encoding via libilbc [no]
> +  --enable-libklvanc       enable Kernel Labs VANC processing [no]
>   --enable-libkvazaar      enable HEVC encoding via libkvazaar [no]
>   --enable-libmodplug      enable ModPlug via libmodplug [no]
>   --enable-libmp3lame      enable MP3 encoding via libmp3lame [no]
> @@ -1603,6 +1604,7 @@ EXTERNAL_LIBRARY_LIST="
>     libgsm
>     libiec61883
>     libilbc
> +    libklvanc
>     libkvazaar
>     libmodplug
>     libmp3lame
> @@ -6027,6 +6029,7 @@ enabled libx264           && { use_pkg_config libx264 x264 "stdint.h x264.h" x26
> enabled libx265           && require_pkg_config libx265 x265 x265.h x265_api_get &&
>                              require_cpp_condition x265.h "X265_BUILD >= 68"
> enabled libxavs           && require libxavs "stdint.h xavs.h" xavs_encoder_encode -lxavs
> +enabled libklvanc         && require libklvanc libklvanc/vanc.h vanc_context_create -lklvanc
> enabled libxvid           && require libxvid xvid.h xvid_global -lxvidcore
> enabled libzimg           && require_pkg_config libzimg "zimg >= 2.3.0" zimg.h zimg_get_api_version
> enabled libzmq            && require_pkg_config libzmq libzmq zmq.h zmq_ctx_new
> diff --git a/libavcodec/v210enc.c b/libavcodec/v210enc.c
> index a6afbbfc41..44cc3c5c81 100644
> --- a/libavcodec/v210enc.c
> +++ b/libavcodec/v210enc.c
> @@ -123,6 +123,7 @@ static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
>     int aligned_width = ((avctx->width + 47) / 48) * 48;
>     int stride = aligned_width * 8 / 3;
>     int line_padding = stride - ((avctx->width * 8 + 11) / 12) * 4;
> +    AVFrameSideData *side_data = NULL;

initializer seems unnecesarry.

>     int h, w, ret;
>     uint8_t *dst;
> 
> @@ -233,6 +234,13 @@ static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
>         }
>     }
> 
> +    side_data = av_frame_get_side_data(pic, AV_FRAME_DATA_A53_CC);
> +    if (side_data && side_data->size) {
> +        uint8_t* buf = av_packet_new_side_data(pkt, AV_PKT_DATA_A53_CC, side_data->size);
> +        if (buf)
> +            memcpy(buf, side_data->data, side_data->size);

else
     return AVERROR(ENOMEM)?

> +    }
> +
>     pkt->flags |= AV_PKT_FLAG_KEY;
>     *got_packet = 1;
>     return 0;
> diff --git a/libavdevice/decklink_common.h b/libavdevice/decklink_common.h
> index 6b2525fb53..285a244000 100644
> --- a/libavdevice/decklink_common.h
> +++ b/libavdevice/decklink_common.h
> @@ -78,6 +78,7 @@ struct decklink_ctx {
>     AVStream *audio_st;
>     AVStream *video_st;
>     AVStream *teletext_st;
> +    uint16_t cdp_sequence_num;
>
>     /* Options */
>     int list_devices;
> diff --git a/libavdevice/decklink_enc.cpp b/libavdevice/decklink_enc.cpp
> index 81df563b3b..3049e936a9 100644
> --- a/libavdevice/decklink_enc.cpp
> +++ b/libavdevice/decklink_enc.cpp
> @@ -38,16 +38,20 @@ extern "C" {
> 
> #include "decklink_common.h"
> #include "decklink_enc.h"
> -
> +#if CONFIG_LIBKLVANC
> +#include "libklvanc/vanc.h"
> +#include "libklvanc/vanc-lines.h"
> +#include "libklvanc/pixels.h"
> +#endif
> 
> /* DeckLink callback class declaration */
> class decklink_frame : public IDeckLinkVideoFrame
> {
> public:
>     decklink_frame(struct decklink_ctx *ctx, AVFrame *avframe, AVCodecID codec_id, int height, int width) :
> -        _ctx(ctx), _avframe(avframe), _avpacket(NULL), _codec_id(codec_id), _height(height), _width(width),  _refs(1) { }
> +        _ctx(ctx), _avframe(avframe), _avpacket(NULL), _codec_id(codec_id), _ancillary(NULL), _height(height), _width(width),  _refs(1) { }
>     decklink_frame(struct decklink_ctx *ctx, AVPacket *avpacket, AVCodecID codec_id, int height, int width) :
> -        _ctx(ctx), _avframe(NULL), _avpacket(avpacket), _codec_id(codec_id), _height(height), _width(width), _refs(1) { }
> +        _ctx(ctx), _avframe(NULL), _avpacket(avpacket), _codec_id(codec_id), _ancillary(NULL), _height(height), _width(width), _refs(1) { }
>
>     virtual long           STDMETHODCALLTYPE GetWidth      (void)          { return _width; }
>     virtual long           STDMETHODCALLTYPE GetHeight     (void)          { return _height; }
> @@ -87,8 +91,13 @@ public:
>     }
>
>     virtual HRESULT STDMETHODCALLTYPE GetTimecode     (BMDTimecodeFormat format, IDeckLinkTimecode **timecode) { return S_FALSE; }
> -    virtual HRESULT STDMETHODCALLTYPE GetAncillaryData(IDeckLinkVideoFrameAncillary **ancillary)               { return S_FALSE; }
> -
> +    virtual HRESULT STDMETHODCALLTYPE GetAncillaryData(IDeckLinkVideoFrameAncillary **ancillary)
> +    {
> +        *ancillary = _ancillary;
> +        return _ancillary ? S_OK : S_FALSE;
> +    }
> +    virtual HRESULT STDMETHODCALLTYPE SetAncillaryData(IDeckLinkVideoFrameAncillary
> +                                                       *ancillary) { _ancillary = ancillary; return S_OK; }
>     virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, LPVOID *ppv) { return E_NOINTERFACE; }
>     virtual ULONG   STDMETHODCALLTYPE AddRef(void)                            { return ++_refs; }
>     virtual ULONG   STDMETHODCALLTYPE Release(void)
> @@ -106,6 +115,7 @@ public:
>     AVFrame *_avframe;
>     AVPacket *_avpacket;
>     AVCodecID _codec_id;
> +    IDeckLinkVideoFrameAncillary *_ancillary;
>     int _height;
>     int _width;
> 
> @@ -169,7 +179,7 @@ static int decklink_setup_video(AVFormatContext *avctx, AVStream *st)
>         return -1;
>     }
>     if (ctx->dlo->EnableVideoOutput(ctx->bmd_mode,
> -                                    bmdVideoOutputFlagDefault) != S_OK) {
> +                                    bmdVideoOutputVANC) != S_OK) {

Are you sure this does not fail of the hardware has no support for 
Ancillary data?

>         av_log(avctx, AV_LOG_ERROR, "Could not enable video output!\n");
>         return -1;
>     }
> @@ -265,6 +275,93 @@ av_cold int ff_decklink_write_trailer(AVFormatContext *avctx)
>     return 0;
> }
> 
> +#if CONFIG_LIBKLVANC
> +static int decklink_construct_vanc(struct decklink_ctx *ctx, AVPacket *pkt,
> +                                   decklink_frame *frame)
> +{
> +    struct vanc_line_set_s vanc_lines;
> +    memset(&vanc_lines, 0, sizeof(vanc_lines));

maybe struct xx = {0}; instead?

> +
> +    int size;
> +    const uint8_t *data = av_packet_get_side_data(pkt, AV_PKT_DATA_A53_CC, &size);
> +    if (data) {
> +        struct packet_eia_708b_s *pkt;
> +        uint16_t *cdp;
> +        uint16_t len;
> +        uint8_t cc_count = size / 3;

I'd put an upper limit to cc_count to be sure I won't overwrite 
something...

> +
> +        klvanc_create_eia708_cdp(&pkt);

Missing error check

> +        klvanc_set_framerate_EIA_708B(pkt, ctx->bmd_tb_num, ctx->bmd_tb_den);

Missing error check. I have not checked, but it is possible that 
you have to av_reduce() on the timebase before calling set_frame_rate to 
get rid of "1000/25000"-like time bases.

> +
> +        /* CC data */
> +        pkt->header.ccdata_present = 1;
> +        pkt->ccdata.cc_count = cc_count;
> +        for (size_t i = 0; i < cc_count; i++) {
> +            if (data [3*i] & 0x40)
> +                pkt->ccdata.cc[i].cc_valid = 1;
> +            pkt->ccdata.cc[i].cc_type = data[3*i] & 0x03;
> +            pkt->ccdata.cc[i].cc_data[0] = data[3*i+1];
> +            pkt->ccdata.cc[i].cc_data[1] = data[3*i+2];
> +        }
> +
> +        klvanc_finalize_EIA_708B(pkt, ctx->cdp_sequence_num++);
> +        convert_EIA_708B_to_words(pkt, &cdp, &len);
> +        klvanc_destroy_eia708_cdp(pkt);
> +
> +        vanc_line_insert(&vanc_lines, cdp, len, 11, 0);

Maybe some error checks here as well?

> +    }
> +
> +    IDeckLinkVideoFrameAncillary *vanc;
> +    int result = ctx->dlo->CreateAncillaryData(bmdFormat10BitYUV, &vanc);

I guess this might fail if the card or the output has no 10 bit anicllary 
data support. So instead of outputting ancillary data always, maybe it is 
better to introduce a new option to be able to enable it explicitly but 
disable it by default?

> +    if (result != S_OK) {
> +        fprintf(stderr, "Failed to create vanc\n");

av_log

> +        return -1;
> +    }
> +
> +    /* Now that we've got all the VANC lines in a nice orderly manner, generate the
> +       final VANC sections for the Decklink output */
> +    for (int i = 0; i < vanc_lines.num_lines; i++) {
> +        struct vanc_line_s *line = vanc_lines.lines[i];
> +        uint16_t *out_line;
> +        int real_line;
> +        int out_len;
> +        void *buf;
> +
> +        if (line == NULL)
> +            break;
> +
> +        real_line = line->line_number;
> +#if 0
> +        /* FIXME: include hack for certain Decklink cards which mis-represent
> +           line numbers for pSF frames */
> +        if (decklink_sys->b_psf_interlaced)
> +            real_line = Calculate1080psfVancLine(line->line_number);
> +#endif
> +        result = vanc->GetBufferForVerticalBlankingLine(real_line, &buf);
> +        if (result != S_OK) {
> +            fprintf(stderr, "Failed to get VANC line %d: %d", real_line, result);

av_log

> +            vanc_line_free(line);
> +            continue;
> +        }
> +
> +        /* Generate the full line taking into account all VANC packets on that line */
> +        generate_vanc_line(line, &out_line, &out_len, ctx->bmd_width);

Error checks...

> +
> +        /* Repack the 16-bit ints into 10-bit, and push into final buffer */
> +        klvanc_y10_to_v210(out_line, (uint8_t *) buf, out_len);
> +        free(out_line);
> +        vanc_line_free(line);
> +    }
> +
> +    result = frame->SetAncillaryData(vanc);
> +    if (result != S_OK) {
> +        fprintf(stderr, "Failed to set vanc: %d", result);
> +        return AVERROR(EIO);
> +    }
> +    return 0;
> +}
> +#endif
> +
> static int decklink_write_video_packet(AVFormatContext *avctx, AVPacket *pkt)
> {
>     struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
> @@ -299,6 +396,10 @@ static int decklink_write_video_packet(AVFormatContext *avctx, AVPacket *pkt)
>         }
>
>         frame = new decklink_frame(ctx, avpacket, st->codecpar->codec_id, ctx->bmd_height, ctx->bmd_width);
> +
> +#if CONFIG_LIBKLVANC
> +        decklink_construct_vanc(ctx, pkt, frame);

Fail on error here as well?

> +#endif

Missing docs update.

Regards,
Marton

>     }
>
>     if (!frame) {
> -- 
> 2.13.2
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel


More information about the ffmpeg-devel mailing list