WebM VP8 Codec SDK
VP8 API 1.x Migration

Version 2.x of this library has deprecated or removed a number of interfaces to the VP8 codec. Where possible, the old interfaces have been left in place in a deprecated state, and will generate compiler warnings when they are referenced. All users are encouraged to update their code to the new interfaces as soon as possible. To assist in this effort, the VPX_CODEC_DISABLE_COMPAT symbol can be #defined to 1 prior to including vpx headers. This will disable the backwards compatability workarounds and ensure that you are using only the latest API.

The TWO-PASS STATISTICS sections detail the one section of code which is not backwards compatable and will require code changes.

HEADER FILES

The following header files were renamed:

vp8.h  -> vp8dx.h
vp8e.h -> vp8cx.h

INTERFACE SYMBOLS

The following interface symbols were renamed:

vpx_codec_vp8_algo -> vpx_codec_vp8_dx_algo
vpx_enc_vp8_algo   -> vpx_codec_vp8_cx_algo

TWO-PASS STATISTICS

Two-pass statistics are handled significantly differently. The version 1 API stored statistics in a file, and the application passed the name of that file in the vpx_codec_enc_cfg structure. In this version, statistics are returned though the application though the vpx_codec_get_cx_data() interface. The application must concatenate these packets into a contiguous buffer and then pass that buffer to the encoder through the vpx_codec_enc_cfg structure on the second pass initialization. The application may choose to keep these packets in memory or write them to disk. Statistics packets are approximately 112 bytes per frame. See the example code for more detailed examples.

ENCODER CONTROLS

Renames

The following controls are duplicated between the encoder and the decoder, but the encoder unnecessarily introduced unique identifiers for them. These identifiers were removed in favor of the ones used by the decoder:

VP8E_SET_REFERENCE  -> VP8_SET_REFERENCE
VP8E_COPY_REFERENCE -> VP8_COPY_REFERENCE
VP8E_SET_PREVIEWPP  -> VP8_SET_POSTPROC

VP8E_SET_FRAMETYPE

This control was removed in favor of the flags parameter to vpx_codec_encode(). Existing code such as:

    vpx_codec_control(&encoder, VP8E_SET_FRAMETYPE, KEY_FRAME);
    ...
    vpx_codec_encode(&encoder, img, pts, 1, 0, 0);

becomes:

    vpx_codec_encode(&encoder, img, pts, 1, VPX_EFLAG_FORCE_KF,
    VPX_DL_REALTIME);

VP8E_SET_FLUSHFLAG

Flush is handled by passing NULL to the img parameter of vpx_codec_encode(). You must do this at least once, regardless of your encoder configuration. i.e. it’s not specific to g_lag_in_frames. This control was removed.

    while(...) {
       ...
       vpx_codec_encode(&encoder, img, pts, 1, 0, 0);
       while( (pkt = vpx_codec_get_cx_data(&encoder, &iter)) ) {
          ...
       }
    }
    vpx_codec_control(&encoder, VP8E_SET_FLUSHFLAG, 1);
    while( (pkt = vpx_codec_get_cx_data(&encoder, &iter)) ) {
       ...
    }
    vpx_codec_encode(&encoder, img, pts, 1, 0, 0);

becomes

    while(new_image && ...) {
       ...
       vpx_codec_encode(&encoder, new_image?img:NULL, pts, 1, 0, 0);
       while( (pkt = vpx_codec_get_cx_data(&encoder, &iter)) ) {
          ...
       }
    }

VP8E_SET_ENCODING_MODE

This control was removed in favor of the deadline parameter to vpx_codec_encode(). There are three macros that can be used to get the equivalent behavior: VPX_DL_REALTIME, VPX_DL_GOOD_QUALITY, VPX_DL_BEST_QUALITY. Existing code such as:

    vpx_codec_control(&encoder, VP8E_SET_ENCODING_MODE, VP8_REAL_TIME_ENCODING);
    ...
    vpx_codec_encode(&encoder, img, pts, 1, 0, 0);

becomes:

    vpx_codec_encode(&encoder, img, pts, 1, 0, VPX_DL_REALTIME);

VP8E_UPD_ENTROPY

This control was deprecated in favor of the flags parameter to vpx_codec_encode(). Existing code such as:

    vpx_codec_control(&encoder, VP8E_UPD_ENTROPY, 0);

becomes:

    vpx_codec_encode(&encoder, img, pts, 1, VP8_EFLAG_NO_UPD_ENTROPY,
                     VPX_DL_REALTIME);

VP8E_UPD_REFERENCE

This control was deprecated in favor of the flags parameter to vpx_codec_encode(). A set bit on the VP8E_UPD_REFERENCE bitfield is analogous to setting the VP8_EFLAG_FORCE_* flag. A cleared bit is analogous to setting the VP8_EFLAG_NO_UPD_* flag. If neither the FORCE or NO_UPD bit is set, the encoder will make its decision automatically, as usual. Setting both bits will result in an error being returned. Existing code such as:

    vpx_codec_control(&encoder, VP8E_UPD_REFERENCE,
                      VP8_LAST_FRAME | VP8_GOLD_FRAME);
    vpx_codec_control(&encoder, VP8E_UPD_REFERENCE, 0);
    ...
    vpx_codec_encode(&encoder, img, pts, 1, 0, VPX_DL_REALTIME);

becomes:

    vpx_codec_encode(&encoder, img, pts, 1, VP8_EFLAG_FORCE_GF,
                     VPX_DL_REALTIME);
    vpx_codec_encode(&encoder, img, pts, 1, VP8_EFLAG_NO_UPD_LAST
                     | VP8_EFLAG_NO_UPD_GF | VP8_EFLAG_NO_UPD_ARF,
                     VPX_DL_REALTIME);

VP8E_USE_REFERENCE

This control was deprecated in favor of the flags parameter to vpx_codec_encode(). A cleared bit on the VP8E_USE_REFERENCE bitfield is analogous to setting the VP8_EFLAG_NO_REF* flag. A set bit indicates that the encoder will make its decision automatically, as usual. Existing code such as:

    vpx_codec_control(&encoder, VP8E_USE_REFERENCE,
                      VP8_ALTR_FRAME | VP8_GOLD_FRAME);
    ...
    vpx_codec_encode(&encoder, img, pts, 1, 0, VPX_DL_REALTIME);

becomes

    vpx_codec_encode(&encoder, img, pts, 1, VP8_EFLAG_NO_REF_LAST,
                     VPX_DL_REALTIME);