static int frame_start(MpegEncContext *s) { int ret; /* mark & release old frames */ if (s->pict_type != AV_PICTURE_TYPE_B && s->last_picture_ptr && s->last_picture_ptr != s->next_picture_ptr && s->last_picture_ptr->f.buf[0]) { ff_mpeg_unref_picture(s, s->last_picture_ptr); } s->current_picture_ptr->f.pict_type = s->pict_type; s->current_picture_ptr->f.key_frame = s->pict_type == AV_PICTURE_TYPE_I; ff_mpeg_unref_picture(s, &s->current_picture); if ((ret = ff_mpeg_ref_picture(s, &s->current_picture, s->current_picture_ptr)) < 0) return ret; if (s->pict_type != AV_PICTURE_TYPE_B) { s->last_picture_ptr = s->next_picture_ptr; if (!s->droppable) s->next_picture_ptr = s->current_picture_ptr; } if (s->last_picture_ptr) { ff_mpeg_unref_picture(s, &s->last_picture); if (s->last_picture_ptr->f.buf[0] && (ret = ff_mpeg_ref_picture(s, &s->last_picture, s->last_picture_ptr)) < 0) return ret; } if (s->next_picture_ptr) { ff_mpeg_unref_picture(s, &s->next_picture); if (s->next_picture_ptr->f.buf[0] && (ret = ff_mpeg_ref_picture(s, &s->next_picture, s->next_picture_ptr)) < 0) return ret; } if (s->picture_structure!= PICT_FRAME) { int i; for (i = 0; i < 4; i++) { if (s->picture_structure == PICT_BOTTOM_FIELD) { s->current_picture.f.data[i] += s->current_picture.f.linesize[i]; } s->current_picture.f.linesize[i] *= 2; s->last_picture.f.linesize[i] *= 2; s->next_picture.f.linesize[i] *= 2; } } if (s->mpeg_quant || s->codec_id == AV_CODEC_ID_MPEG2VIDEO) { s->dct_unquantize_intra = s->dct_unquantize_mpeg2_intra; s->dct_unquantize_inter = s->dct_unquantize_mpeg2_inter; } else if (s->out_format == FMT_H263 || s->out_format == FMT_H261) { s->dct_unquantize_intra = s->dct_unquantize_h263_intra; s->dct_unquantize_inter = s->dct_unquantize_h263_inter; } else { s->dct_unquantize_intra = s->dct_unquantize_mpeg1_intra; s->dct_unquantize_inter = s->dct_unquantize_mpeg1_inter; } if (s->dct_error_sum) { assert(s->avctx->noise_reduction && s->encoding); update_noise_reduction(s); } return 0; }