@@ -48,6 +48,7 @@ version <next>:

 - cropdetect filter

 - ffmpeg -crop* options removed

 - transpose filter added

+- ffmpeg -force_key_frames option added

 version 0.6:

@@ -495,6 +495,12 @@ Bitstream filters available are "dump_extra", "remove_extra", "noise", "h264_mp4

 @example

 ffmpeg -i h264.mp4 -vcodec copy -vbsf h264_mp4toannexb -an out.h264

 @end example

+@item -force_key_frames @var{time}[,@var{time}...]

+Force key frames at the specified timestamps, more precisely at the first

+frames after each specified time.

+This option can be useful to ensure that a seek point is present at a

+chapter mark or any other designated place in the output file.

+The timestamps must be specified in ascending order.

 @end table

 @section Audio Options

@@ -225,6 +225,7 @@ static int nb_frames_drop = 0;

 static int input_sync;

 static uint64_t limit_filesize = 0;

 static int force_fps = 0;

+static char *forced_key_frames = NULL;

 static int pgmyuv_compatibility_hack=0;

 static float dts_delta_threshold = 10;

@@ -272,6 +273,11 @@ typedef struct AVOutputStream {

     int original_height;

     int original_width;

+    /* forced key frames */

+    int64_t *forced_kf_pts;

+    int forced_kf_count;

+    int forced_kf_index;

+

     /* audio only */

     int audio_resample;

     ReSampleContext *resample; /* for audio resampling */

@@ -1189,6 +1195,11 @@ static void do_video_out(AVFormatContext *s,

             big_picture.pts= ost->sync_opts;

 //            big_picture.pts= av_rescale(ost->sync_opts, AV_TIME_BASE*(int64_t)enc->time_base.num, enc->time_base.den);

 //av_log(NULL, AV_LOG_DEBUG, "%"PRId64" -> encoder\n", ost->sync_opts);

+            if (ost->forced_kf_index < ost->forced_kf_count &&

+                big_picture.pts >= ost->forced_kf_pts[ost->forced_kf_index]) {

+                big_picture.pict_type = FF_I_TYPE;

+                ost->forced_kf_index++;

+            }

             ret = avcodec_encode_video(enc,

                                        bit_buffer, bit_buffer_size,

                                        &big_picture);

@@ -1837,6 +1848,29 @@ static int copy_chapters(int infile, int outfile)

     return 0;

 }

+static void parse_forced_key_frames(char *kf, AVOutputStream *ost,

+                                    AVCodecContext *avctx)

+{

+    char *p;

+    int n = 1, i;

+    int64_t t;

+

+    for (p = kf; *p; p++)

+        if (*p == ',')

+            n++;

+    ost->forced_kf_count = n;

+    ost->forced_kf_pts = av_malloc(sizeof(*ost->forced_kf_pts) * n);

+    if (!ost->forced_kf_pts) {

+        av_log(NULL, AV_LOG_FATAL, "Could not allocate forced key frames array.\n");

+        ffmpeg_exit(1);

+    }

+    for (i = 0; i < n; i++) {

+        p = i ? strchr(p, ',') + 1 : kf;

+        t = parse_time_or_die("force_key_frames", p, 1);

+        ost->forced_kf_pts[i] = av_rescale_q(t, AV_TIME_BASE_Q, avctx->time_base);

+    }

+}

+

 /*

  * The following code is the main loop of the file converter

  */

@@ -2578,6 +2612,7 @@ static int transcode(AVFormatContext **output_files,

                 av_fifo_free(ost->fifo); /* works even if fifo is not

                                              initialized but set to zero */

                 av_free(ost->pict_tmp.data[0]);

+                av_free(ost->forced_kf_pts);

                 if (ost->video_resample)

                     sws_freeContext(ost->img_resample_ctx);

                 if (ost->resample)

@@ -3333,6 +3368,9 @@ static void new_video_stream(AVFormatContext *oc, int file_idx)

                 video_enc->flags |= CODEC_FLAG_PASS2;

             }

         }

+

+        if (forced_key_frames)

+            parse_forced_key_frames(forced_key_frames, ost, video_enc);

     }

     if (video_language) {

         av_metadata_set2(&st->metadata, "language", video_language, 0);

@@ -3342,6 +3380,7 @@ static void new_video_stream(AVFormatContext *oc, int file_idx)

     /* reset some key parameters */

     video_disable = 0;

     av_freep(&video_codec_name);

+    av_freep(&forced_key_frames);

     video_stream_copy = 0;

     frame_pix_fmt = PIX_FMT_NONE;

 }

@@ -3644,6 +3683,7 @@ static void opt_output_file(const char *filename)

     set_context_opts(oc, avformat_opts, AV_OPT_FLAG_ENCODING_PARAM, NULL);

     nb_streamid_map = 0;

+    av_freep(&forced_key_frames);

 }

 /* same option as mencoder */

@@ -4094,6 +4134,7 @@ static const OptionDef options[] = {

     { "qphist", OPT_BOOL | OPT_EXPERT | OPT_VIDEO, { (void *)&qp_hist }, "show QP histogram" },

     { "force_fps", OPT_BOOL | OPT_EXPERT | OPT_VIDEO, {(void*)&force_fps}, "force the selected framerate, disable the best supported framerate selection" },

     { "streamid", OPT_FUNC2 | HAS_ARG | OPT_EXPERT, {(void*)opt_streamid}, "set the value of an outfile streamid", "streamIndex:value" },

+    { "force_key_frames", OPT_STRING | HAS_ARG | OPT_EXPERT | OPT_VIDEO, {(void *)&forced_key_frames}, "force key frames at specified timestamps", "timestamps" },

     /* audio options */

     { "ab", OPT_FUNC2 | HAS_ARG | OPT_AUDIO, {(void*)opt_bitrate}, "set bitrate (in bits/s)", "bitrate" },