[FFmpeg-devel] [PATCH 1/3] avcodec/ccaption_dec: rework non-real-time mode with pop-on captions by delaying
Paul B Mahol
onemda at gmail.com
Fri Jun 19 17:26:48 EEST 2020
So it give similar output as visual output of real-time mode.
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
libavcodec/ccaption_dec.c | 117 ++++++++++++++++++++++----------------
1 file changed, 68 insertions(+), 49 deletions(-)
diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c
index 87ac23e0d1..e67a47508c 100644
--- a/libavcodec/ccaption_dec.c
+++ b/libavcodec/ccaption_dec.c
@@ -231,27 +231,25 @@ typedef struct CCaptionSubContext {
uint8_t cursor_color;
uint8_t cursor_font;
uint8_t cursor_charset;
- AVBPrint buffer;
+ AVBPrint buffer[2];
+ int buffer_index;
int buffer_changed;
int rollup;
enum cc_mode mode;
- int64_t start_time;
- /* visible screen time */
- int64_t startv_time;
- int64_t end_time;
+ int64_t buffer_time[2];
int screen_touched;
int64_t last_real_time;
char prev_cmd[2];
int readorder;
} CCaptionSubContext;
-
static av_cold int init_decoder(AVCodecContext *avctx)
{
int ret;
CCaptionSubContext *ctx = avctx->priv_data;
- av_bprint_init(&ctx->buffer, 0, AV_BPRINT_SIZE_UNLIMITED);
+ av_bprint_init(&ctx->buffer[0], 0, AV_BPRINT_SIZE_UNLIMITED);
+ av_bprint_init(&ctx->buffer[1], 0, AV_BPRINT_SIZE_UNLIMITED);
/* taking by default roll up to 2 */
ctx->mode = CCMODE_ROLLUP;
ctx->rollup = 2;
@@ -275,7 +273,8 @@ static av_cold int init_decoder(AVCodecContext *avctx)
static av_cold int close_decoder(AVCodecContext *avctx)
{
CCaptionSubContext *ctx = avctx->priv_data;
- av_bprint_finalize(&ctx->buffer, NULL);
+ av_bprint_finalize(&ctx->buffer[0], NULL);
+ av_bprint_finalize(&ctx->buffer[1], NULL);
return 0;
}
@@ -299,7 +298,8 @@ static void flush_decoder(AVCodecContext *avctx)
ctx->buffer_changed = 0;
if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP))
ctx->readorder = 0;
- av_bprint_clear(&ctx->buffer);
+ av_bprint_clear(&ctx->buffer[0]);
+ av_bprint_clear(&ctx->buffer[1]);
}
/**
@@ -427,7 +427,9 @@ static int capture_screen(CCaptionSubContext *ctx)
struct Screen *screen = ctx->screen + ctx->active_screen;
enum cc_font prev_font = CCFONT_REGULAR;
enum cc_color_code prev_color = CCCOL_WHITE;
- av_bprint_clear(&ctx->buffer);
+ const int bidx = ctx->buffer_index;
+
+ av_bprint_clear(&ctx->buffer[bidx]);
for (i = 0; screen->row_used && i < SCREEN_ROWS; i++)
{
@@ -459,7 +461,7 @@ static int capture_screen(CCaptionSubContext *ctx)
x = ASS_DEFAULT_PLAYRESX * (0.1 + 0.0250 * j);
y = ASS_DEFAULT_PLAYRESY * (0.1 + 0.0533 * i);
- av_bprintf(&ctx->buffer, "{\\an7}{\\pos(%d,%d)}", x, y);
+ av_bprintf(&ctx->buffer[bidx], "{\\an7}{\\pos(%d,%d)}", x, y);
for (; j < SCREEN_COLUMNS; j++) {
const char *e_tag = "", *s_tag = "", *c_tag = "";
@@ -521,35 +523,33 @@ static int capture_screen(CCaptionSubContext *ctx)
prev_color = color[j];
override = charset_overrides[(int)charset[j]][(int)row[j]];
if (override) {
- av_bprintf(&ctx->buffer, "%s%s%s%s", e_tag, s_tag, c_tag, override);
+ av_bprintf(&ctx->buffer[bidx], "%s%s%s%s", e_tag, s_tag, c_tag, override);
seen_char = 1;
} else if (row[j] == ' ' && !seen_char) {
- av_bprintf(&ctx->buffer, "%s%s%s\\h", e_tag, s_tag, c_tag);
+ av_bprintf(&ctx->buffer[bidx], "%s%s%s\\h", e_tag, s_tag, c_tag);
} else {
- av_bprintf(&ctx->buffer, "%s%s%s%c", e_tag, s_tag, c_tag, row[j]);
+ av_bprintf(&ctx->buffer[bidx], "%s%s%s%c", e_tag, s_tag, c_tag, row[j]);
seen_char = 1;
}
}
- av_bprintf(&ctx->buffer, "\\N");
+ av_bprintf(&ctx->buffer[bidx], "\\N");
}
}
- if (!av_bprint_is_complete(&ctx->buffer))
+ if (!av_bprint_is_complete(&ctx->buffer[bidx]))
return AVERROR(ENOMEM);
- if (screen->row_used && ctx->buffer.len >= 2) {
- ctx->buffer.len -= 2;
- ctx->buffer.str[ctx->buffer.len] = 0;
+ if (screen->row_used && ctx->buffer[bidx].len >= 2) {
+ ctx->buffer[bidx].len -= 2;
+ ctx->buffer[bidx].str[ctx->buffer[bidx].len] = 0;
}
ctx->buffer_changed = 1;
return 0;
}
-static int reap_screen(CCaptionSubContext *ctx, int64_t pts)
+static void update_time(CCaptionSubContext *ctx, int64_t pts)
{
- ctx->start_time = ctx->startv_time;
- ctx->startv_time = pts;
- ctx->end_time = pts;
- return capture_screen(ctx);
+ ctx->buffer_time[0] = ctx->buffer_time[1];
+ ctx->buffer_time[1] = pts;
}
static void handle_textattr(CCaptionSubContext *ctx, uint8_t hi, uint8_t lo)
@@ -594,10 +594,7 @@ static void handle_pac(CCaptionSubContext *ctx, uint8_t hi, uint8_t lo)
}
}
-/**
- * @param pts it is required to set end time
- */
-static int handle_edm(CCaptionSubContext *ctx, int64_t pts)
+static int handle_edm(CCaptionSubContext *ctx)
{
struct Screen *screen = ctx->screen + ctx->active_screen;
int ret;
@@ -605,35 +602,35 @@ static int handle_edm(CCaptionSubContext *ctx, int64_t pts)
// In buffered mode, keep writing to screen until it is wiped.
// Before wiping the display, capture contents to emit subtitle.
if (!ctx->real_time)
- ret = reap_screen(ctx, pts);
+ ret = capture_screen(ctx);
screen->row_used = 0;
// In realtime mode, emit an empty caption so the last one doesn't
// stay on the screen.
if (ctx->real_time)
- ret = reap_screen(ctx, pts);
+ ret = capture_screen(ctx);
return ret;
}
-static int handle_eoc(CCaptionSubContext *ctx, int64_t pts)
+static int handle_eoc(CCaptionSubContext *ctx)
{
int ret;
ctx->active_screen = !ctx->active_screen;
// In buffered mode, we wait til the *next* EOC and
- // reap what was already on the screen since the last EOC.
+ // capture what was already on the screen since the last EOC.
if (!ctx->real_time)
- ret = handle_edm(ctx, pts);
+ ret = handle_edm(ctx);
ctx->cursor_column = 0;
// In realtime mode, we display the buffered contents (after
// flipping the buffer to active above) as soon as EOC arrives.
if (ctx->real_time)
- ret = reap_screen(ctx, pts);
+ ret = capture_screen(ctx);
return ret;
}
@@ -684,7 +681,7 @@ static void handle_char(CCaptionSubContext *ctx, char hi, char lo)
ff_dlog(ctx, "(%c)\n", hi);
}
-static int process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint8_t lo)
+static int process_cc608(CCaptionSubContext *ctx, uint8_t hi, uint8_t lo)
{
int ret = 0;
@@ -727,13 +724,13 @@ static int process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint8
break;
case 0x2c:
/* erase display memory */
- handle_edm(ctx, pts);
+ handle_edm(ctx);
break;
case 0x2d:
/* carriage return */
ff_dlog(ctx, "carriage return\n");
if (!ctx->real_time)
- ret = reap_screen(ctx, pts);
+ ret = capture_screen(ctx);
roll_up(ctx);
ctx->cursor_column = 0;
break;
@@ -749,7 +746,7 @@ static int process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint8
case 0x2f:
/* end of caption */
ff_dlog(ctx, "handle_eoc\n");
- ret = handle_eoc(ctx, pts);
+ ret = handle_eoc(ctx);
break;
default:
ff_dlog(ctx, "Unknown command 0x%hhx 0x%hhx\n", hi, lo);
@@ -780,7 +777,10 @@ static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avp
{
CCaptionSubContext *ctx = avctx->priv_data;
AVSubtitle *sub = data;
- const int64_t start_time = sub->pts;
+ int64_t in_time = sub->pts;
+ int64_t start_time;
+ int64_t end_time;
+ int bidx = ctx->buffer_index;
uint8_t *bptr = NULL;
int len = avpkt->size;
int ret = 0;
@@ -796,7 +796,7 @@ static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avp
if (cc_type == 1)
continue;
- ret = process_cc608(ctx, start_time, bptr[i + 1] & 0x7f, bptr[i + 2] & 0x7f);
+ ret = process_cc608(ctx, bptr[i + 1] & 0x7f, bptr[i + 2] & 0x7f);
if (ret < 0)
return ret;
@@ -804,23 +804,41 @@ static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avp
continue;
ctx->buffer_changed = 0;
- if (ctx->buffer.str[0] || ctx->real_time) {
- ff_dlog(ctx, "cdp writing data (%s)\n", ctx->buffer.str);
- ret = ff_ass_add_rect(sub, ctx->buffer.str, ctx->readorder++, 0, NULL, NULL);
- if (ret < 0)
- return ret;
- sub->pts = ctx->start_time;
+ if (!ctx->real_time && ctx->mode == CCMODE_POPON)
+ ctx->buffer_index = bidx = !ctx->buffer_index;
+
+ update_time(ctx, in_time);
+
+ if (ctx->buffer[bidx].str[0] || ctx->real_time) {
+ ff_dlog(ctx, "cdp writing data (%s)\n", ctx->buffer[bidx].str);
+ start_time = ctx->buffer_time[0];
+ sub->pts = start_time;
+ end_time = ctx->buffer_time[1];
if (!ctx->real_time)
- sub->end_display_time = av_rescale_q(ctx->end_time - ctx->start_time,
+ sub->end_display_time = av_rescale_q(end_time - start_time,
AV_TIME_BASE_Q, ms_tb);
else
sub->end_display_time = -1;
- ctx->buffer_changed = 0;
+ ret = ff_ass_add_rect(sub, ctx->buffer[bidx].str, ctx->readorder++, 0, NULL, NULL);
+ if (ret < 0)
+ return ret;
ctx->last_real_time = sub->pts;
ctx->screen_touched = 0;
}
}
+ if (!bptr && !ctx->real_time && ctx->buffer[!ctx->buffer_index].str[0]) {
+ bidx = !ctx->buffer_index;
+ ret = ff_ass_add_rect(sub, ctx->buffer[bidx].str, ctx->readorder++, 0, NULL, NULL);
+ if (ret < 0)
+ return ret;
+ sub->pts = ctx->buffer_time[1];
+ sub->end_display_time = av_rescale_q(ctx->buffer_time[1] - ctx->buffer_time[0],
+ AV_TIME_BASE_Q, ms_tb);
+ if (sub->end_display_time == 0)
+ sub->end_display_time = ctx->buffer[bidx].len * 20;
+ }
+
if (ctx->real_time && ctx->screen_touched &&
sub->pts > ctx->last_real_time + av_rescale_q(200, ms_tb, AV_TIME_BASE_Q)) {
ctx->last_real_time = sub->pts;
@@ -829,7 +847,7 @@ static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avp
capture_screen(ctx);
ctx->buffer_changed = 0;
- ret = ff_ass_add_rect(sub, ctx->buffer.str, ctx->readorder++, 0, NULL, NULL);
+ ret = ff_ass_add_rect(sub, ctx->buffer[bidx].str, ctx->readorder++, 0, NULL, NULL);
if (ret < 0)
return ret;
sub->end_display_time = -1;
@@ -864,4 +882,5 @@ AVCodec ff_ccaption_decoder = {
.flush = flush_decoder,
.decode = decode,
.priv_class = &ccaption_dec_class,
+ .capabilities = AV_CODEC_CAP_DELAY,
};
--
2.17.1
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