From: Karthick J <kjeya...@akamai.com>
In preparation to support multiple VANC data decode
Signed-off-by: Karthick J <kjeya...@akamai.com>
---
libavdevice/decklink_dec.cpp | 31 ++++++++++++++++++-------------
1 file changed, 18 insertions(+), 13 deletions(-)
diff --git a/libavdevice/decklink_dec.cpp b/libavdevice/decklink_dec.cpp
index 40ef655..0b88fc8 100644
--- a/libavdevice/decklink_dec.cpp
+++ b/libavdevice/decklink_dec.cpp
@@ -106,6 +106,18 @@ static void get_vanc_lines(int bmd_field_dominance, int
height, int *field0_vanc
}
}
+/* The 10-bit VANC data is packed in V210, we only need the luma component. */
+static void extract_luma_from_v210(uint16_t *dst, const uint8_t *src, int
width)
+{
+ int i;
+ for (i = 0; i < width / 3; i += 3) {
+ *dst++ = (src[1] >> 2) + ((src[2] & 15) << 6);
+ *dst++ = src[4] + ((src[5] & 3) << 8);
+ *dst++ = (src[6] >> 4) + ((src[7] & 63) << 4);
+ src += 8;
+ }
+}
+
static uint8_t calc_parity_and_line_offset(int line)
{
uint8_t ret = (line < 313) << 5;
@@ -221,19 +233,10 @@ static uint8_t*
teletext_data_unit_from_ancillary_packet(uint16_t *py, uint16_t
return tgt;
}
-static uint8_t* teletext_data_unit_from_vanc_data(uint8_t *src, uint8_t *tgt,
int64_t wanted_lines)
+static uint8_t* teletext_data_unit_from_vanc_data(uint16_t *py, uint8_t *tgt,
int64_t wanted_lines)
{
- uint16_t y[1920];
- uint16_t *py = y;
- uint16_t *pend = y + 1920;
- /* The 10-bit VANC data is packed in V210, we only need the luma
component. */
- while (py < pend) {
- *py++ = (src[1] >> 2) + ((src[2] & 15) << 6);
- *py++ = src[4] + ((src[5] & 3) << 8);
- *py++ = (src[6] >> 4) + ((src[7] & 63) << 4);
- src += 8;
- }
- py = y;
+ uint16_t *pend = py + 1920;
+
while (py < pend - 6) {
if (py[0] == 0 && py[1] == 0x3ff && py[2] == 0x3ff) { //
ancillary data flag
py += 3;
@@ -570,8 +573,10 @@ HRESULT decklink_input_callback::VideoInputFrameArrived(
for (i = 0; i <= vanc_end; i++) {
uint8_t *buf;
if (vanc->GetBufferForVerticalBlankingLine(i,
(void**)&buf) == S_OK) {
+ uint16_t luma_vanc[4096]; // Allocated for highest
width (4K)
+ extract_luma_from_v210(luma_vanc, buf,
videoFrame->GetWidth());
if (videoFrame->GetWidth() == 1920) {
- txt_buf =
teletext_data_unit_from_vanc_data(buf, txt_buf, ctx->teletext_lines);
+ txt_buf =
teletext_data_unit_from_vanc_data(luma_vanc, txt_buf, ctx->teletext_lines);
if (txt_buf - txt_buf0 > 1611) { // ensure
we still have at least 1920 bytes free in the buffer
av_log(avctx, AV_LOG_ERROR, "Too many OP47
teletext packets.\n");
break;
--
1.9.1
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