#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "avdevice.h"
+#include "timefilter.h"
#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"
#include "libavutil/avstring.h"
#define V4L_RAWFORMATS 1
#define V4L_COMPFORMATS 2
+/**
+ * Return timestamps to the user exactly as returned by the kernel
+ */
+#define V4L_TS_DEFAULT 0
+/**
+ * Autodetect the kind of timestamps returned by the kernel and convert to
+ * absolute (wall clock) timestamps.
+ */
+#define V4L_TS_ABS 1
+/**
+ * Assume kernel timestamps are from the monotonic clock and convert to
+ * absolute timestamps.
+ */
+#define V4L_TS_MONO2ABS 2
+
+/**
+ * Once the kind of timestamps returned by the kernel have been detected,
+ * the value of the timefilter (NULL or not) determines whether a conversion
+ * takes place.
+ */
+#define V4L_TS_CONVERT_READY V4L_TS_DEFAULT
+
struct video_data {
AVClass *class;
int fd;
int frame_size;
int interlaced;
int top_field_first;
+ int ts_mode;
+ TimeFilter *timefilter;
+ int64_t last_time_m;
int buffers;
void **buf_start;
static struct fmt_map fmt_conversion_table[] = {
//ff_fmt codec_id v4l2_fmt
{ PIX_FMT_YUV420P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420 },
+ { PIX_FMT_YUV420P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YVU420 },
{ PIX_FMT_YUV422P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P },
{ PIX_FMT_YUYV422, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUYV },
{ PIX_FMT_UYVY422, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_UYVY },
pkt->size = 0;
}
+#if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
+static int64_t av_gettime_monotonic(void)
+{
+ struct timespec tv;
+
+ clock_gettime(CLOCK_MONOTONIC, &tv);
+ return (int64_t)tv.tv_sec * 1000000 + tv.tv_nsec / 1000;
+}
+#endif
+
+static int init_convert_timestamp(AVFormatContext *ctx, int64_t ts)
+{
+ struct video_data *s = ctx->priv_data;
+ int64_t now;
+
+ now = av_gettime();
+ if (s->ts_mode == V4L_TS_ABS &&
+ ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE) {
+ av_log(ctx, AV_LOG_INFO, "Detected absolute timestamps\n");
+ s->ts_mode = V4L_TS_CONVERT_READY;
+ return 0;
+ }
+#if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
+ now = av_gettime_monotonic();
+ if (s->ts_mode == V4L_TS_MONO2ABS ||
+ (ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE)) {
+ int64_t period = av_rescale_q(1, ctx->streams[0]->codec->time_base,
+ AV_TIME_BASE_Q);
+ av_log(ctx, AV_LOG_INFO, "Detected monotonic timestamps, converting\n");
+ /* microseconds instead of seconds, MHz instead of Hz */
+ s->timefilter = ff_timefilter_new(1, period, 1.0E-6);
+ s->ts_mode = V4L_TS_CONVERT_READY;
+ return 0;
+ }
+#endif
+ av_log(ctx, AV_LOG_ERROR, "Unknown timestamps\n");
+ return AVERROR(EIO);
+}
+
+static int convert_timestamp(AVFormatContext *ctx, int64_t *ts)
+{
+ struct video_data *s = ctx->priv_data;
+
+ if (s->ts_mode) {
+ int r = init_convert_timestamp(ctx, *ts);
+ if (r < 0)
+ return r;
+ }
+#if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
+ if (s->timefilter) {
+ int64_t nowa = av_gettime();
+ int64_t nowm = av_gettime_monotonic();
+ ff_timefilter_update(s->timefilter, nowa, nowm - s->last_time_m);
+ s->last_time_m = nowm;
+ *ts = ff_timefilter_eval(s->timefilter, *ts - nowm);
+ }
+#endif
+ return 0;
+}
+
static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
{
struct video_data *s = ctx->priv_data;
pkt->data= s->buf_start[buf.index];
pkt->size = buf.bytesused;
pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
+ res = convert_timestamp(ctx, &pkt->pts);
+ if (res < 0)
+ return res;
pkt->destruct = mmap_release_buffer;
buf_descriptor = av_malloc(sizeof(struct buff_data));
if (buf_descriptor == NULL) {
if (codec_id == CODEC_ID_RAWVIDEO)
st->codec->codec_tag =
avcodec_pix_fmt_to_codec_tag(st->codec->pix_fmt);
+ if (desired_format == V4L2_PIX_FMT_YVU420)
+ st->codec->codec_tag = MKTAG('Y', 'V', '1', '2');
st->codec->width = s->width;
st->codec->height = s->height;
st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
{ "all", "Show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.dbl = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
{ "raw", "Show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.dbl = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
{ "compressed", "Show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.dbl = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
+ { "timestamps", "Kind of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.dbl = 0 }, 0, 2, DEC, "timestamps" },
+ { "default", "Use timestamps from the kernel", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.dbl = V4L_TS_DEFAULT }, 0, 2, DEC, "timestamps" },
+ { "abs", "Use absolute timestamps (wall clock)", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.dbl = V4L_TS_ABS }, 0, 2, DEC, "timestamps" },
+ { "mono2abs", "Force conversion from monotonic to absolute timestamps", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.dbl = V4L_TS_MONO2ABS }, 0, 2, DEC, "timestamps" },
+ { "ts", "Kind of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.dbl = 0 }, 0, 2, DEC, "timestamps" },
{ NULL },
};
projects / ffmpeg / blobdiff