=====Codec Flags====
Defined in ''avcodec.h''

<code c>
#define CODEC_FLAG_QSCALE 0x0002  ///< Use fixed qscale.
#define CODEC_FLAG_4MV    0x0004  ///< 4 MV per MB allowed / advanced prediction for H.263.
#define CODEC_FLAG_QPEL   0x0010  ///< Use qpel MC.
#define CODEC_FLAG_GMC    0x0020  ///< Use GMC.
#define CODEC_FLAG_MV0    0x0040  ///< Always try a MB with MV=<0,0>.
#define CODEC_FLAG_PART   0x0080  ///< Use data partitioning.
/**
 * The parent program guarantees that the input for B-frames containing
 * streams is not written to for at least s->max_b_frames+1 frames, if
 * this is not set the input will be copied.
 */
#define CODEC_FLAG_INPUT_PRESERVED 0x0100
#define CODEC_FLAG_PASS1           0x0200   ///< Use internal 2pass ratecontrol in first pass mode.
#define CODEC_FLAG_PASS2           0x0400   ///< Use internal 2pass ratecontrol in second pass mode.
#define CODEC_FLAG_EXTERN_HUFF     0x1000   ///< Use external Huffman table (for MJPEG).
#define CODEC_FLAG_GRAY            0x2000   ///< Only decode/encode grayscale.
#define CODEC_FLAG_EMU_EDGE        0x4000   ///< Don't draw edges.
#define CODEC_FLAG_PSNR            0x8000   ///< error[?] variables will be set during encoding.
#define CODEC_FLAG_TRUNCATED       0x00010000 /** Input bitstream might be truncated at a random
                                                  location instead of only at frame boundaries. */
#define CODEC_FLAG_NORMALIZE_AQP  0x00020000 ///< Normalize adaptive quantization.
#define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
#define CODEC_FLAG_LOW_DELAY      0x00080000 ///< Force low delay.
#define CODEC_FLAG_ALT_SCAN       0x00100000 ///< Use alternate scan.
#define CODEC_FLAG_TRELLIS_QUANT  0x00200000 ///< Use trellis quantization.
#define CODEC_FLAG_GLOBAL_HEADER  0x00400000 ///< Place global headers in extradata instead of every keyframe.
#define CODEC_FLAG_BITEXACT       0x00800000 ///< Use only bitexact stuff (except (I)DCT).
/* Fx : Flag for h263+ extra options */
#if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)
#define CODEC_FLAG_H263P_AIC      0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction (remove this)
#endif
#define CODEC_FLAG_AC_PRED        0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
#define CODEC_FLAG_H263P_UMV      0x02000000 ///< unlimited motion vector
#define CODEC_FLAG_CBP_RD         0x04000000 ///< Use rate distortion optimization for cbp.
#define CODEC_FLAG_QP_RD          0x08000000 ///< Use rate distortion optimization for qp selectioon.
#define CODEC_FLAG_H263P_AIV      0x00000008 ///< H.263 alternative inter VLC
#define CODEC_FLAG_OBMC           0x00000001 ///< OBMC
#define CODEC_FLAG_LOOP_FILTER    0x00000800 ///< loop filter
#define CODEC_FLAG_H263P_SLICE_STRUCT 0x10000000
#define CODEC_FLAG_INTERLACED_ME  0x20000000 ///< interlaced motion estimation
#define CODEC_FLAG_SVCD_SCAN_OFFSET 0x40000000 ///< Will reserve space for SVCD scan offset user data.
#define CODEC_FLAG_CLOSED_GOP     ((int)0x80000000)
#define CODEC_FLAG2_FAST          0x00000001 ///< Allow non spec compliant speedup tricks.
#define CODEC_FLAG2_STRICT_GOP    0x00000002 ///< Strictly enforce GOP size.
#define CODEC_FLAG2_NO_OUTPUT     0x00000004 ///< Skip bitstream encoding.
#define CODEC_FLAG2_LOCAL_HEADER  0x00000008 ///< Place global headers at every keyframe instead of in extradata.
#define CODEC_FLAG2_BPYRAMID      0x00000010 ///< H.264 allow B-frames to be used as references.
#define CODEC_FLAG2_WPRED         0x00000020 ///< H.264 weighted biprediction for B-frames
#define CODEC_FLAG2_MIXED_REFS    0x00000040 ///< H.264 one reference per partition, as opposed to one reference per macroblock
#define CODEC_FLAG2_8X8DCT        0x00000080 ///< H.264 high profile 8x8 transform
#define CODEC_FLAG2_FASTPSKIP     0x00000100 ///< H.264 fast pskip
#define CODEC_FLAG2_AUD           0x00000200 ///< H.264 access unit delimiters
#define CODEC_FLAG2_BRDO          0x00000400 ///< B-frame rate-distortion optimization
#define CODEC_FLAG2_INTRA_VLC     0x00000800 ///< Use MPEG-2 intra VLC table.
#define CODEC_FLAG2_MEMC_ONLY     0x00001000 ///< Only do ME/MC (I frames -> ref, P frame -> ME+MC).
#define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format.
#define CODEC_FLAG2_SKIP_RD       0x00004000 ///< RD optimal MB level residual skipping
#define CODEC_FLAG2_CHUNKS        0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
#define CODEC_FLAG2_NON_LINEAR_QUANT 0x00010000 ///< Use MPEG-2 nonlinear quantizer.
</code>