From: Clément Bœsch <clem...@stupeflix.com>
This function will be used in the following commits in ffmpeg and
ffplay.
---
cmdutils.c | 170 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
cmdutils.h | 12 +++++
2 files changed, 182 insertions(+)
diff --git a/cmdutils.c b/cmdutils.c
index b35180e..0e22e57 100644
--- a/cmdutils.c
+++ b/cmdutils.c
@@ -31,7 +31,9 @@
#include "config.h"
#include "compat/va_copy.h"
+#include "libavcodec/bytestream.h"
#include "libavformat/avformat.h"
+#include "libavformat/isom.h"
#include "libavfilter/avfilter.h"
#include "libavdevice/avdevice.h"
#include "libavresample/avresample.h"
@@ -2252,3 +2254,171 @@ int show_sinks(void *optctx, const char *opt, const
char *arg)
return ret;
}
#endif
+
+static int parse_elst(MOVElst **ret, const uint8_t *buf, int size)
+{
+ GetByteContext gb;
+ int i, edit_count, version;
+ MOVElst *elst_data;
+
+ bytestream2_init(&gb, buf, size);
+
+ version = bytestream2_get_byte(&gb);
+ bytestream2_skip(&gb, 3); /* flags */
+ edit_count = bytestream2_get_be32(&gb);
+
+ if (!edit_count)
+ return 0;
+
+ elst_data = av_malloc_array(edit_count, sizeof(*elst_data));
+ if (!elst_data)
+ return AVERROR(ENOMEM);
+
+ for (i = 0; i < edit_count && bytestream2_get_bytes_left(&gb) > 0; i++) {
+ MOVElst *e = &elst_data[i];
+
+ if (version == 1) {
+ e->duration = bytestream2_get_be64(&gb);
+ e->time = bytestream2_get_be64(&gb);
+ } else {
+ e->duration = bytestream2_get_be32(&gb);
+ e->time = (int32_t)bytestream2_get_be32(&gb);
+ }
+ e->rate = bytestream2_get_be32(&gb) / 65536.0;
+ }
+
+ *ret = elst_data;
+ return i;
+}
+
+static int get_elst_lavfi_graph_str(AVBPrint *bp, const AVStream *st, int64_t
start_time)
+{
+ int i, elst_count, size;
+ AVBPrint select;
+ AVBPrint setpts;
+ MOVElst *elst;
+ AVRational tb;
+
+ const uint8_t *buf = av_stream_get_side_data(st, AV_PKT_DATA_MOV_TIMELINE,
&size);
+ if (!buf || size <= 4)
+ return 0;
+
+ tb = av_make_q(1, AV_RB32(buf));
+
+ elst_count = parse_elst(&elst, buf + 4, size - 4);
+ if (elst_count <= 0)
+ return elst_count;
+
+ av_bprint_init(bp, 0, AV_BPRINT_SIZE_UNLIMITED);
+ av_bprint_init(&select, 0, AV_BPRINT_SIZE_UNLIMITED);
+ av_bprint_init(&setpts, 0, AV_BPRINT_SIZE_UNLIMITED);
+
+ for (i = 0; i < elst_count; i++) {
+ int64_t gap;
+ const MOVElst *segment = &elst[i];
+ const MOVElst *next = i < elst_count - 1 ? &elst[i + 1] : NULL;
+ const MOVElst *prev = i > 0 ? &elst[i - 1] : NULL;
+ int64_t rescaled_start = av_rescale_q(segment->time, tb,
st->time_base);
+ int64_t end = segment->duration ? segment->time + segment->duration :
-1;
+
+ if (!segment->duration && next)
+ end = next->time;
+
+ if (select.str[0]) {
+ av_bprintf(&select, "+");
+ } if (end == -1) {
+ av_bprintf(&select, "gte(pts,%"PRId64")", rescaled_start);
+ } else {
+ const int64_t rescaled_end = av_rescale_q(end, tb, st->time_base);
+ av_bprintf(&select, "between(pts,%"PRId64",%"PRId64"-1)",
+ rescaled_start, rescaled_end);
+ }
+
+ if (segment->time == -1)
+ /* XXX: we are supposed to insert initial silence/emptiness here */
+ gap = segment->duration;
+ else if (prev)
+ gap = segment->time - prev->time - prev->duration;
+ else
+ gap = segment->time;
+ gap *= segment->rate;
+
+ if (gap) {
+ if (!*setpts.str)
+ av_bprintf(&setpts, "PTS");
+ gap = av_rescale_q(gap, tb, st->time_base);
+ av_bprintf(&setpts, "-if(gte(PTS,%"PRId64"),%"PRId64",0)",
+ segment->time, gap);
+ }
+ }
+
+ av_freep(&elst);
+
+ if (select.str[0] && av_bprint_is_complete(&select) &&
av_bprint_is_complete(&setpts)) {
+ const char *tstr = st->codec->codec_type == AVMEDIA_TYPE_AUDIO ? "a" :
"";
+ int64_t rescaled_start_time = start_time == AV_NOPTS_VALUE ? 0 :
av_rescale_q(start_time, AV_TIME_BASE_Q, st->time_base);
+
+ av_bprintf(bp, "[tl_in] ");
+
+ /* make sure the following filters will not take into account the PTS
+ * shift that can occur with ffmpeg (-ss) */
+ if (rescaled_start_time)
+ av_bprintf(bp, "%ssetpts=PTS+%"PRId64", ", tstr,
rescaled_start_time);
+
+ /* select the time ranges
+ * FIXME: aselect should be replaced with a sample accurate filter */
+ av_bprintf(bp, "%sselect='%s'", tstr, select.str);
+
+ /* insert the time adjustment filter if there are time time gaps (often
+ * the case if there is more than one entry) */
+ if (setpts.str[0])
+ av_bprintf(bp, ", %ssetpts='%s'", tstr, setpts.str);
+
+ /* restore the time shift introduced previously */
+ if (rescaled_start_time)
+ av_bprintf(bp, ", %ssetpts=PTS-%"PRId64, tstr,
rescaled_start_time);
+
+ av_bprintf(bp, " [tl_out]");
+ }
+
+ av_bprint_finalize(&select, NULL);
+ av_bprint_finalize(&setpts, NULL);
+
+ return 0;
+}
+
+int insert_timeline_graph(const AVStream *st, AVFilterContext **last_filter,
+ int64_t start_time, int reverse)
+{
+ AVBPrint bp;
+ AVFilterInOut *inputs, *outputs;
+ AVFilterGraph *graph = (*last_filter)->graph;
+
+ int ret = get_elst_lavfi_graph_str(&bp, st, start_time);
+ if (ret < 0)
+ goto end;
+
+ if (!av_bprint_is_complete(&bp) || !bp.str[0])
+ goto end;
+
+ if ((ret = avfilter_graph_parse2(graph, bp.str, &inputs, &outputs)) < 0) {
+ av_log(NULL, AV_LOG_ERROR, "Unable to parse timeline graph\n");
+ goto end;
+ }
+
+ if (reverse) ret = avfilter_link(outputs[0].filter_ctx, 0, *last_filter,
0);
+ else ret = avfilter_link(*last_filter, 0, inputs[0].filter_ctx, 0);
+
+ if (ret < 0) {
+ av_log(NULL, AV_LOG_ERROR, "Unable to link the end of the timeline "
+ "graph to the last inserted filter: %s\n", av_err2str(ret));
+ goto end;
+ }
+
+ if (reverse) *last_filter = inputs[0].filter_ctx;
+ else *last_filter = outputs[0].filter_ctx;
+
+end:
+ av_bprint_finalize(&bp, NULL);
+ return ret;
+}
diff --git a/cmdutils.h b/cmdutils.h
index f6ad44c..7b140fd 100644
--- a/cmdutils.h
+++ b/cmdutils.h
@@ -597,4 +597,16 @@ void *grow_array(void *array, int elem_size, int *size,
int new_size);
char name[128];\
av_get_channel_layout_string(name, sizeof(name), 0, ch_layout);
+/**
+ * Get the MOV timeline from the stream side data, construct a libavfilter
+ * filtergraph, and insert it after the last filter.
+ *
+ * @param st the stream with the timeline
+ * @param last_filter pointer to last filter to stick the filtergraph (will be
updated)
+ * @param start_time initial timestamp offset in AV_TIME_BASE_Q time base
+ * @param reverse if set, prepend the timeline filtergraph instead of
appending it
+ */
+int insert_timeline_graph(const AVStream *st, AVFilterContext **last_filter,
+ int64_t start_time, int reverse);
+
#endif /* CMDUTILS_H */
--
2.2.1
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