Index: source/libvpx/examples/simple_encoder.c |
=================================================================== |
--- source/libvpx/examples/simple_encoder.c (revision 263011) |
+++ source/libvpx/examples/simple_encoder.c (working copy) |
@@ -64,6 +64,15 @@ |
// frame is shown for one frame-time in duration. The flags parameter is |
// unused in this example. The deadline is set to VPX_DL_REALTIME to |
// make the example run as quickly as possible. |
+ |
+// Forced Keyframes |
+// ---------------- |
+// Keyframes can be forced by setting the VPX_EFLAG_FORCE_KF bit of the |
+// flags passed to `vpx_codec_control()`. In this example, we force a |
+// keyframe every <keyframe-interval> frames. Note, the output stream can |
+// contain additional keyframes beyond those that have been forced using the |
+// VPX_EFLAG_FORCE_KF flag because of automatic keyframe placement by the |
+// encoder. |
// |
// Processing The Encoded Data |
// --------------------------- |
@@ -103,8 +112,8 @@ |
void usage_exit() { |
fprintf(stderr, |
"Usage: %s <codec> <width> <height> <infile> <outfile> " |
- "[<error-resilient>]\nSee comments in simple_encoder.c for more " |
- "information.\n", |
+ "<keyframe-interval> [<error-resilient>]\nSee comments in " |
+ "simple_encoder.c for more information.\n", |
exec_name); |
exit(EXIT_FAILURE); |
} |
@@ -112,11 +121,12 @@ |
static void encode_frame(vpx_codec_ctx_t *codec, |
vpx_image_t *img, |
int frame_index, |
+ int flags, |
VpxVideoWriter *writer) { |
vpx_codec_iter_t iter = NULL; |
const vpx_codec_cx_pkt_t *pkt = NULL; |
- const vpx_codec_err_t res = vpx_codec_encode(codec, img, frame_index, 1, 0, |
- VPX_DL_GOOD_QUALITY); |
+ const vpx_codec_err_t res = vpx_codec_encode(codec, img, frame_index, 1, |
+ flags, VPX_DL_GOOD_QUALITY); |
if (res != VPX_CODEC_OK) |
die_codec(codec, "Failed to encode frame"); |
@@ -148,15 +158,20 @@ |
const VpxInterface *encoder = NULL; |
const int fps = 30; // TODO(dkovalev) add command line argument |
const int bitrate = 200; // kbit/s TODO(dkovalev) add command line argument |
+ int keyframe_interval = 0; |
+ |
+ // TODO(dkovalev): Add some simple command line parsing code to make the |
+ // command line more flexible. |
const char *codec_arg = NULL; |
const char *width_arg = NULL; |
const char *height_arg = NULL; |
const char *infile_arg = NULL; |
const char *outfile_arg = NULL; |
+ const char *keyframe_interval_arg = NULL; |
exec_name = argv[0]; |
- if (argc < 6) |
+ if (argc < 7) |
die("Invalid number of arguments"); |
codec_arg = argv[1]; |
@@ -164,6 +179,7 @@ |
height_arg = argv[3]; |
infile_arg = argv[4]; |
outfile_arg = argv[5]; |
+ keyframe_interval_arg = argv[6]; |
encoder = get_vpx_encoder_by_name(codec_arg); |
if (!encoder) |
@@ -187,6 +203,10 @@ |
die("Failed to allocate image."); |
} |
+ keyframe_interval = strtol(keyframe_interval_arg, NULL, 0); |
+ if (keyframe_interval < 0) |
+ die("Invalid keyframe interval value."); |
+ |
printf("Using %s\n", vpx_codec_iface_name(encoder->interface())); |
res = vpx_codec_enc_config_default(encoder->interface(), &cfg, 0); |
@@ -198,7 +218,7 @@ |
cfg.g_timebase.num = info.time_base.numerator; |
cfg.g_timebase.den = info.time_base.denominator; |
cfg.rc_target_bitrate = bitrate; |
- cfg.g_error_resilient = argc > 6 ? strtol(argv[6], NULL, 0) : 0; |
+ cfg.g_error_resilient = argc > 7 ? strtol(argv[7], NULL, 0) : 0; |
writer = vpx_video_writer_open(outfile_arg, kContainerIVF, &info); |
if (!writer) |
@@ -210,9 +230,13 @@ |
if (vpx_codec_enc_init(&codec, encoder->interface(), &cfg, 0)) |
die_codec(&codec, "Failed to initialize encoder"); |
- while (vpx_img_read(&raw, infile)) |
- encode_frame(&codec, &raw, frame_count++, writer); |
- encode_frame(&codec, NULL, -1, writer); // flush the encoder |
+ while (vpx_img_read(&raw, infile)) { |
+ int flags = 0; |
+ if (keyframe_interval > 0 && frame_count % keyframe_interval == 0) |
+ flags |= VPX_EFLAG_FORCE_KF; |
+ encode_frame(&codec, &raw, frame_count++, flags, writer); |
+ } |
+ encode_frame(&codec, NULL, -1, 0, writer); // flush the encoder |
printf("\n"); |
fclose(infile); |