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avdevice/decklink_dec: add support for decoding teletext from 10bit ancillary data

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This also add supports for 4K DeckLink cards because they always output the
ancillary data in 10-bit.

v2:
- only try teletext decoding for 576i PAL mode
- some comments as requested by Aaron Levinson

Signed-off-by: Marton Balint <cus@passwd.hu>
This commit is contained in:
Marton Balint 2017-06-24 16:57:18 +02:00
parent 4c1aac893c
commit cc0916bfc2
2 changed files with 48 additions and 19 deletions
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4
doc/indevs.texi
View File

@ -250,8 +250,8 @@ specifically lines 6 to 22, and lines 318 to 335. Line 6 is the LSB in the mask.
Selected lines which do not contain teletext information will be ignored. You
can use the special @option{all} constant to select all possible lines, or
@option{standard} to skip lines 6, 318 and 319, which are not compatible with all
receivers. Capturing teletext only works for SD PAL sources in 8 bit mode.
To use this option, ffmpeg needs to be compiled with @code{--enable-libzvbi}.
receivers. Capturing teletext only works for SD PAL sources. To use this
option, ffmpeg needs to be compiled with @code{--enable-libzvbi}.
@item channels
Defines number of audio channels to capture. Must be @samp{2}, @samp{8} or @samp{16}.

63
libavdevice/decklink_dec.cpp
View File

@ -30,6 +30,7 @@ extern "C" {
extern "C" {
#include "config.h"
#include "libavformat/avformat.h"
#include "libavutil/avassert.h"
#include "libavutil/avutil.h"
#include "libavutil/common.h"
#include "libavutil/imgutils.h"
@ -54,21 +55,43 @@ static uint8_t calc_parity_and_line_offset(int line)
return ret;
}
int teletext_data_unit_from_vbi_data(int line, uint8_t *src, uint8_t *tgt)
static void fill_data_unit_head(int line, 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;
static uint8_t* teletext_data_unit_from_vbi_data(int line, uint8_t *src, uint8_t *tgt, vbi_pixfmt fmt)
{
vbi_bit_slicer slicer;
vbi_bit_slicer_init(&slicer, 720, 13500000, 6937500, 6937500, 0x00aaaae4, 0xffff, 18, 6, 42 * 8, VBI_MODULATION_NRZ_MSB, fmt);
if (vbi_bit_slice(&slicer, src, tgt + 4) == FALSE)
return tgt;
fill_data_unit_head(line, tgt);
return tgt + 46;
}
static uint8_t* teletext_data_unit_from_vbi_data_10bit(int line, uint8_t *src, uint8_t *tgt)
{
uint8_t y[720];
uint8_t *py = y;
uint8_t *pend = y + 720;
/* The 10-bit VBI data is packed in V210, but libzvbi only supports 8-bit,
* so we extract the 8 MSBs of the luma component, that is enough for
* teletext bit slicing. */
while (py < pend) {
*py++ = (src[1] >> 4) + ((src[2] & 15) << 4);
*py++ = (src[4] >> 2) + ((src[5] & 3 ) << 6);
*py++ = (src[6] >> 6) + ((src[7] & 63) << 2);
src += 8;
}
return teletext_data_unit_from_vbi_data(line, y, tgt, VBI_PIXFMT_YUV420);
}
#endif
@ -359,7 +382,7 @@ HRESULT decklink_input_callback::VideoInputFrameArrived(
//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) {
if (!no_video && ctx->teletext_lines) {
IDeckLinkVideoFrameAncillary *vanc;
AVPacket txt_pkt;
uint8_t txt_buf0[1611]; // max 35 * 46 bytes decoded teletext lines + 1 byte data_identifier
@ -368,16 +391,22 @@ HRESULT decklink_input_callback::VideoInputFrameArrived(
if (videoFrame->GetAncillaryData(&vanc) == S_OK) {
int i;
int64_t line_mask = 1;
BMDPixelFormat vanc_format = vanc->GetPixelFormat();
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 (ctx->bmd_mode == bmdModePAL && (vanc_format == bmdFormat8BitYUV || vanc_format == bmdFormat10BitYUV)) {
av_assert0(videoFrame->GetWidth() == 720);
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 (vanc_format == bmdFormat8BitYUV)
txt_buf = teletext_data_unit_from_vbi_data(i, buf, txt_buf, VBI_PIXFMT_UYVY);
else
txt_buf = teletext_data_unit_from_vbi_data_10bit(i, buf, txt_buf);
}
if (i == 22)
i = 317;
}
if (i == 22)
i = 317;
}
vanc->Release();
if (txt_buf - txt_buf0 > 1) {