Rashad Tatum:
> Add implementation for changing the play rate for rtsp streams.
> ---
> libavformat/avformat.h | 6 ++++++
> libavformat/demux.h | 6 ++++++
> libavformat/demux_utils.c | 6 ++++++
> libavformat/rtsp.c | 1 +
> libavformat/rtsp.h | 10 ++++++++++
> libavformat/rtspdec.c | 21 +++++++++++++++++++--
> 6 files changed, 48 insertions(+), 2 deletions(-)
>
> diff --git a/libavformat/avformat.h b/libavformat/avformat.h
> index 2034d2aecc..7819b61d3e 100644
> --- a/libavformat/avformat.h
> +++ b/libavformat/avformat.h
> @@ -2358,6 +2358,12 @@ int avformat_flush(AVFormatContext *s);
> */
> int av_read_play(AVFormatContext *s);
>
> +/**
> + * Play a network-based stream (e.g. RTSP stream) with a given play rate
> + * (e.g. Scale value for RTSP) and timestamp position.
> + */
> +int av_read_play_with_rate(AVFormatContext *s, double play_rate, int
> stream_index, int64_t timestamp);
> +
> /**
> * Pause a network-based stream (e.g. RTSP stream).
> *
> diff --git a/libavformat/demux.h b/libavformat/demux.h
> index e83d84a201..965743bdf0 100644
> --- a/libavformat/demux.h
> +++ b/libavformat/demux.h
> @@ -113,6 +113,12 @@ typedef struct FFInputFormat {
> * (RTSP).
> */
> int (*read_play)(struct AVFormatContext *);
> +
> + /**
> + * Play a network-based stream (e.g. RTSP stream) with a given play rate
> + * (e.g. Scale value for RTSP) and timestamp position.
> + */
> + int (*read_play_with_rate)(struct AVFormatContext *s, double play_rate,
> int stream_index, int64_t timestamp);
>
> /**
> * Pause playing - only meaningful if using a network-based format
> diff --git a/libavformat/demux_utils.c b/libavformat/demux_utils.c
> index b632277460..8fed41e3b6 100644
> --- a/libavformat/demux_utils.c
> +++ b/libavformat/demux_utils.c
> @@ -179,6 +179,12 @@ int av_read_play(AVFormatContext *s)
> return AVERROR(ENOSYS);
> }
>
> +int av_read_play_with_rate(AVFormatContext *s, double play_rate, int
> stream_index, int64_t timestamp) {
> + if (ffifmt(s->iformat)->read_play_with_rate)
> + return ffifmt(s->iformat)->read_play_with_rate(s, play_rate,
> stream_index, timestamp);
> + return AVERROR(ENOSYS);
> +}
> +
> int av_read_pause(AVFormatContext *s)
> {
> if (ffifmt(s->iformat)->read_pause)
> diff --git a/libavformat/rtsp.c b/libavformat/rtsp.c
> index 5ea471b40c..6cfbcdf989 100644
> --- a/libavformat/rtsp.c
> +++ b/libavformat/rtsp.c
> @@ -1998,6 +1998,7 @@ redirect:
> av_strlcpy(rt->real_challenge, real_challenge,
> sizeof(rt->real_challenge));
> rt->state = RTSP_STATE_IDLE;
> rt->seek_timestamp = 0; /* default is to start stream at position zero */
> + rt->scale = 1.0; /* default is to play at the normal rate */
> return 0;
> fail:
> ff_rtsp_close_streams(s);
> diff --git a/libavformat/rtsp.h b/libavformat/rtsp.h
> index 83b2e3f4fb..1b8ce05d74 100644
> --- a/libavformat/rtsp.h
> +++ b/libavformat/rtsp.h
> @@ -245,6 +245,16 @@ typedef struct RTSPState {
> * whenever we resume playback. Either way, the value is only used once,
> * see rtsp_read_play() and rtsp_read_seek(). */
> int64_t seek_timestamp;
> +
> + /** the scale value requested when calling av_read_play(). This value
> + * is subsequently used as part of the "Scale" parameter when emitting
> + * the RTSP PLAY command. The "Scale" parameter determines the stream
> play
> + * rate. A value of 1 represents the normal play rate. Any other value
> is
> + * in regards to the normal play rate. A negative value represents
> reverse
> + * playback. If we are currently playing, this command is called
> instantly.
> + * If we are currently paused, this command is called whenever we resume
> + * playback. */
> + double scale;
>
> int seq; /**< RTSP command sequence number */
>
> diff --git a/libavformat/rtspdec.c b/libavformat/rtspdec.c
> index 10078ce2fa..f1e44ccb63 100644
> --- a/libavformat/rtspdec.c
> +++ b/libavformat/rtspdec.c
> @@ -39,6 +39,7 @@
> #include "tls.h"
> #include "url.h"
> #include "version.h"
> +#include <stdio.h>
>
> static const struct RTSPStatusMessage {
> enum RTSPStatusCode code;
> @@ -527,7 +528,7 @@ static int rtsp_read_play(AVFormatContext *s)
> {
> RTSPState *rt = s->priv_data;
> RTSPMessageHeader reply1, *reply = &reply1;
> - int i;
> + int i, cmd_char_count = 0;
> char cmd[MAX_URL_SIZE];
>
> av_log(s, AV_LOG_DEBUG, "hello state=%d\n", rt->state);
> @@ -564,11 +565,17 @@ static int rtsp_read_play(AVFormatContext *s)
> if (rt->state == RTSP_STATE_PAUSED) {
> cmd[0] = 0;
> } else {
> - snprintf(cmd, sizeof(cmd),
> +
> + cmd_char_count += snprintf(cmd, sizeof(cmd),
> "Range: npt=%"PRId64".%03"PRId64"-\r\n",
> rt->seek_timestamp / AV_TIME_BASE,
> rt->seek_timestamp / (AV_TIME_BASE / 1000) % 1000);
> +
> + snprintf(cmd + cmd_char_count, sizeof(cmd) - cmd_char_count,
> "Scale: %f\r\n", rt->scale);
> +
> }
> +
> +
> ff_rtsp_send_cmd(s, "PLAY", rt->control_uri, cmd, reply, NULL);
> if (reply->status_code != RTSP_STATUS_OK) {
> return ff_rtsp_averror(reply->status_code, -1);
> @@ -593,6 +600,15 @@ static int rtsp_read_play(AVFormatContext *s)
> return 0;
> }
>
> +static int rtsp_read_play_with_rate(AVFormatContext *s, double play_rate,
> int stream_index, int64_t timestamp) {
> + RTSPState *rt = s->priv_data;
> + rt->seek_timestamp = av_rescale_q(timestamp,
> + s->streams[stream_index]->time_base,
> + AV_TIME_BASE_Q);
> + rt->scale = play_rate;
> + return rtsp_read_play(s);
> +}
> +
> /* pause the stream */
> static int rtsp_read_pause(AVFormatContext *s)
> {
> @@ -1006,5 +1022,6 @@ const FFInputFormat ff_rtsp_demuxer = {
> .read_close = rtsp_read_close,
> .read_seek = rtsp_read_seek,
> .read_play = rtsp_read_play,
> + .read_play_with_rate = rtsp_read_play_with_rate,
> .read_pause = rtsp_read_pause,
> };
Seems like play_rate should just be an option of this demuxer (with the
AV_OPT_FLAG_RUNTIME_PARAM flag).
- Andreas
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
