[FFmpeg-devel] [PATCH v1 1/2] avformat/imfdec: use CPL start timecode if available
pal at sandflow.com
pal at sandflow.com
Tue Aug 23 08:10:49 EEST 2022
From: Pierre-Anthony Lemieux <pal at palemieux.com>
The IMF CPL contains an optional timecode start address. This patch reads the
latter, if present, into the context's timecode metadata parameter.
This addresses https://trac.ffmpeg.org/ticket/9842.
---
libavformat/imf.h | 2 +
libavformat/imf_cpl.c | 109 ++++++++++++++++++++++++++++++++++++++++++
libavformat/imfdec.c | 11 +++++
3 files changed, 122 insertions(+)
diff --git a/libavformat/imf.h b/libavformat/imf.h
index 4271cd9582..70ed007312 100644
--- a/libavformat/imf.h
+++ b/libavformat/imf.h
@@ -59,6 +59,7 @@
#include "libavformat/avio.h"
#include "libavutil/rational.h"
#include "libavutil/uuid.h"
+#include "libavutil/timecode.h"
#include <libxml/tree.h>
/**
@@ -130,6 +131,7 @@ typedef struct FFIMFCPL {
AVUUID id_uuid; /**< CompositionPlaylist/Id element */
xmlChar *content_title_utf8; /**< CompositionPlaylist/ContentTitle element */
AVRational edit_rate; /**< CompositionPlaylist/EditRate element */
+ AVTimecode *tc; /**< CompositionPlaylist/CompositionTimecode element */
FFIMFMarkerVirtualTrack *main_markers_track; /**< Main Marker Virtual Track */
FFIMFTrackFileVirtualTrack *main_image_2d_track; /**< Main Image Virtual Track */
uint32_t main_audio_track_count; /**< Number of Main Audio Virtual Tracks */
diff --git a/libavformat/imf_cpl.c b/libavformat/imf_cpl.c
index 4acc20feee..1868d7db45 100644
--- a/libavformat/imf_cpl.c
+++ b/libavformat/imf_cpl.c
@@ -116,6 +116,25 @@ int ff_imf_xml_read_uint32(xmlNodePtr element, uint32_t *number)
return ret;
}
+static int ff_imf_xml_read_boolean(xmlNodePtr element, int *value)
+{
+ xmlChar *element_text = NULL;
+ int ret = 0;
+
+ element_text = xmlNodeListGetString(element->doc, element->xmlChildrenNode, 1);
+
+ if (xmlStrcmp(element_text, "true") == 0 || xmlStrcmp(element_text, "1") == 0)
+ *value = 1;
+ else if (xmlStrcmp(element_text, "false") == 0 || xmlStrcmp(element_text, "0") == 0)
+ *value = 0;
+ else
+ ret = 1;
+
+ xmlFree(element_text);
+
+ return ret;
+}
+
static void imf_base_virtual_track_init(FFIMFBaseVirtualTrack *track)
{
memset(track->id_uuid, 0, sizeof(track->id_uuid));
@@ -179,6 +198,90 @@ static int fill_content_title(xmlNodePtr cpl_element, FFIMFCPL *cpl)
return 0;
}
+static int digit_to_int(char digit)
+{
+ if (digit >= '0' && digit <= '9')
+ return digit - '0';
+ return -1;
+}
+
+/**
+ * Parses a string that conform to the TimecodeType used in IMF CPL and defined
+ * in SMPTE ST 2067-3.
+ * @param[in] s string to parse
+ * @param[out] tc_comps pointer to an array of 4 integers where the parsed HH,
+ * MM, SS and FF fields of the timecode are returned.
+ * @return 0 on success, < 0 AVERROR code on error.
+ */
+static int parse_cpl_tc_type(const char *s, int *tc_comps)
+{
+ if (av_strnlen(s, 11) != 11)
+ return AVERROR(EINVAL);
+
+ for (int i = 0; i < 4; i++) {
+ int hi;
+ int lo;
+
+ hi = digit_to_int(s[i * 3]);
+ lo = digit_to_int(s[i * 3 + 1]);
+
+ if (hi == -1 || lo == -1)
+ return AVERROR(EINVAL);
+
+ tc_comps[i] = 10 * hi + lo;
+ }
+
+ return 0;
+}
+
+static int fill_timecode(xmlNodePtr cpl_element, FFIMFCPL *cpl)
+{
+ xmlNodePtr tc_element = NULL;
+ xmlNodePtr element = NULL;
+ xmlChar *tc_str = NULL;
+ int df = 0;
+ int comps[4];
+ int ret = 0;
+
+ tc_element = ff_imf_xml_get_child_element_by_name(cpl_element, "CompositionTimecode");
+ if (!tc_element)
+ return 0;
+
+ element = ff_imf_xml_get_child_element_by_name(tc_element, "TimecodeDropFrame");
+ if (!element) {
+ av_log(NULL, AV_LOG_ERROR, "CompositionTimecode element is missing\
+ a TimecodeDropFrame child element\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ if (ff_imf_xml_read_boolean(element, &df)) {
+ av_log(NULL, AV_LOG_ERROR, "TimecodeDropFrame element is invalid\n");
+ return AVERROR_INVALIDDATA;
+ }
+ element = ff_imf_xml_get_child_element_by_name(tc_element, "TimecodeStartAddress");
+ if (!element) {
+ av_log(NULL, AV_LOG_ERROR, "CompositionTimecode element is missing\
+ a TimecodeStartAddress child element\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ tc_str = xmlNodeListGetString(element->doc, element->xmlChildrenNode, 1);
+ ret = parse_cpl_tc_type(tc_str, comps);
+ xmlFree(tc_str);
+ if (ret)
+ return ret;
+
+ cpl->tc = av_malloc(sizeof(AVTimecode));
+ if (!cpl->tc)
+ return AVERROR(ENOMEM);
+ ret = av_timecode_init_from_components(cpl->tc, cpl->edit_rate,
+ df ? AV_TIMECODE_FLAG_DROPFRAME : 0,
+ comps[0], comps[1], comps[2], comps[3],
+ NULL);
+
+ return ret;
+}
+
static int fill_edit_rate(xmlNodePtr cpl_element, FFIMFCPL *cpl)
{
xmlNodePtr element = NULL;
@@ -682,6 +785,8 @@ int ff_imf_parse_cpl_from_xml_dom(xmlDocPtr doc, FFIMFCPL **cpl)
goto cleanup;
if ((ret = fill_edit_rate(cpl_element, *cpl)))
goto cleanup;
+ if ((ret = fill_timecode(cpl_element, *cpl)))
+ goto cleanup;
if ((ret = fill_virtual_tracks(cpl_element, *cpl)))
goto cleanup;
@@ -731,6 +836,7 @@ static void imf_cpl_init(FFIMFCPL *cpl)
av_uuid_nil(cpl->id_uuid);
cpl->content_title_utf8 = NULL;
cpl->edit_rate = av_make_q(0, 1);
+ cpl->tc = NULL;
cpl->main_markers_track = NULL;
cpl->main_image_2d_track = NULL;
cpl->main_audio_track_count = 0;
@@ -753,6 +859,9 @@ void ff_imf_cpl_free(FFIMFCPL *cpl)
if (!cpl)
return;
+ if (cpl->tc)
+ av_freep(&cpl->tc);
+
xmlFree(cpl->content_title_utf8);
imf_marker_virtual_track_free(cpl->main_markers_track);
diff --git a/libavformat/imfdec.c b/libavformat/imfdec.c
index 5bbe7a53f8..fdf9a4e87c 100644
--- a/libavformat/imfdec.c
+++ b/libavformat/imfdec.c
@@ -622,6 +622,8 @@ static int imf_read_header(AVFormatContext *s)
IMFContext *c = s->priv_data;
char *asset_map_path;
char *tmp_str;
+ AVDictionaryEntry* tcr;
+ char tc_buf[AV_TIMECODE_STR_SIZE];
int ret = 0;
c->interrupt_callback = &s->interrupt_callback;
@@ -641,6 +643,15 @@ static int imf_read_header(AVFormatContext *s)
if ((ret = ff_imf_parse_cpl(s->pb, &c->cpl)) < 0)
return ret;
+ tcr = av_dict_get(s->metadata, "timecode", NULL, 0);
+ if (!tcr && c->cpl->tc) {
+ ret = av_dict_set(&s->metadata, "timecode",
+ av_timecode_make_string(c->cpl->tc, tc_buf, 0), 0);
+ if (ret)
+ return ret;
+ av_log(s, AV_LOG_INFO, "Setting timecode to IMF CPL timecode %s\n", tc_buf);
+ }
+
av_log(s,
AV_LOG_DEBUG,
"parsed IMF CPL: " AV_PRI_URN_UUID "\n",
--
2.25.1
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