From dddb5f72a2accc0b956d1ab8c4108745a924e736 Mon Sep 17 00:00:00 2001 From: HolyWu <holywu@gmail.com> Date: Mon, 17 May 2021 11:24:41 +0800 Subject: [PATCH] Revert "vc-1: Optimise parser (with special attention to ARM)" This reverts commit 701e8b42e12ad625c64ceae2252acb1de390278c. The optimized VC-1 parser did not parse properties of pictures at all and it could cause seeking issues. --- libavcodec/vc1_parser.c | 305 +++++++++++++++------------------------- 1 file changed, 115 insertions(+), 190 deletions(-) diff --git a/libavcodec/vc1_parser.c b/libavcodec/vc1_parser.c index 493ffde61104c..7016df06e71da 100644 --- a/libavcodec/vc1_parser.c +++ b/libavcodec/vc1_parser.c @@ -31,98 +31,132 @@ #include "get_bits.h" #include "internal.h" -/** The maximum number of bytes of a sequence, entry point or - * frame header whose values we pay any attention to */ -#define UNESCAPED_THRESHOLD 37 - -/** The maximum number of bytes of a sequence, entry point or - * frame header which must be valid memory (because they are - * used to update the bitstream cache in skip_bits() calls) - */ -#define UNESCAPED_LIMIT 144 - -typedef enum { - NO_MATCH, - ONE_ZERO, - TWO_ZEROS, - ONE -} VC1ParseSearchState; - typedef struct VC1ParseContext { ParseContext pc; VC1Context v; - uint8_t prev_start_code; - size_t bytes_to_skip; - uint8_t unesc_buffer[UNESCAPED_LIMIT]; - size_t unesc_index; - VC1ParseSearchState search_state; } VC1ParseContext; -static void vc1_extract_header(AVCodecParserContext *s, AVCodecContext *avctx, - const uint8_t *buf, int buf_size) +static void vc1_extract_headers(AVCodecParserContext *s, AVCodecContext *avctx, + const uint8_t *buf, int buf_size) { - /* Parse the header we just finished unescaping */ VC1ParseContext *vpc = s->priv_data; GetBitContext gb; - int ret; + const uint8_t *start, *end, *next; + uint8_t *buf2 = av_mallocz(buf_size + AV_INPUT_BUFFER_PADDING_SIZE); + vpc->v.s.avctx = avctx; vpc->v.parse_only = 1; - init_get_bits8(&gb, buf, buf_size); - switch (vpc->prev_start_code) { - case VC1_CODE_SEQHDR & 0xFF: - ff_vc1_decode_sequence_header(avctx, &vpc->v, &gb); - break; - case VC1_CODE_ENTRYPOINT & 0xFF: - ff_vc1_decode_entry_point(avctx, &vpc->v, &gb); - break; - case VC1_CODE_FRAME & 0xFF: - if(vpc->v.profile < PROFILE_ADVANCED) - ret = ff_vc1_parse_frame_header (&vpc->v, &gb); - else - ret = ff_vc1_parse_frame_header_adv(&vpc->v, &gb); - - if (ret < 0) + vpc->v.first_pic_header_flag = 1; + next = buf; + s->repeat_pict = 0; + + for(start = buf, end = buf + buf_size; next < end; start = next){ + int buf2_size, size; + int ret; + + next = find_next_marker(start + 4, end); + size = next - start - 4; + buf2_size = vc1_unescape_buffer(start + 4, size, buf2); + init_get_bits8(&gb, buf2, buf2_size); + if(size <= 0) continue; + switch(AV_RB32(start)){ + case VC1_CODE_SEQHDR: + ff_vc1_decode_sequence_header(avctx, &vpc->v, &gb); + break; + case VC1_CODE_ENTRYPOINT: + ff_vc1_decode_entry_point(avctx, &vpc->v, &gb); break; + case VC1_CODE_FRAME: + if(vpc->v.profile < PROFILE_ADVANCED) + ret = ff_vc1_parse_frame_header (&vpc->v, &gb); + else + ret = ff_vc1_parse_frame_header_adv(&vpc->v, &gb); - /* keep AV_PICTURE_TYPE_BI internal to VC1 */ - if (vpc->v.s.pict_type == AV_PICTURE_TYPE_BI) - s->pict_type = AV_PICTURE_TYPE_B; - else - s->pict_type = vpc->v.s.pict_type; + if (ret < 0) + break; - if (avctx->ticks_per_frame > 1){ - // process pulldown flags - s->repeat_pict = 1; - // Pulldown flags are only valid when 'broadcast' has been set. - // So ticks_per_frame will be 2 - if (vpc->v.rff){ - // repeat field - s->repeat_pict = 2; - }else if (vpc->v.rptfrm){ - // repeat frames - s->repeat_pict = vpc->v.rptfrm * 2 + 1; + /* keep AV_PICTURE_TYPE_BI internal to VC1 */ + if (vpc->v.s.pict_type == AV_PICTURE_TYPE_BI) + s->pict_type = AV_PICTURE_TYPE_B; + else + s->pict_type = vpc->v.s.pict_type; + + if (avctx->ticks_per_frame > 1){ + // process pulldown flags + s->repeat_pict = 1; + // Pulldown flags are only valid when 'broadcast' has been set. + // So ticks_per_frame will be 2 + if (vpc->v.rff){ + // repeat field + s->repeat_pict = 2; + }else if (vpc->v.rptfrm){ + // repeat frames + s->repeat_pict = vpc->v.rptfrm * 2 + 1; + } } - }else{ - s->repeat_pict = 0; + + if (vpc->v.broadcast && vpc->v.interlace && !vpc->v.psf) + s->field_order = vpc->v.tff ? AV_FIELD_TT : AV_FIELD_BB; + else + s->field_order = AV_FIELD_PROGRESSIVE; + + break; + } + if (avctx->framerate.num) + avctx->time_base = av_inv_q(av_mul_q(avctx->framerate, (AVRational){avctx->ticks_per_frame, 1})); + s->format = vpc->v.chromaformat == 1 ? AV_PIX_FMT_YUV420P + : AV_PIX_FMT_NONE; + if (avctx->width && avctx->height) { + s->width = avctx->width; + s->height = avctx->height; + s->coded_width = FFALIGN(avctx->coded_width, 16); + s->coded_height = FFALIGN(avctx->coded_height, 16); } + } - if (vpc->v.broadcast && vpc->v.interlace && !vpc->v.psf) - s->field_order = vpc->v.tff ? AV_FIELD_TT : AV_FIELD_BB; - else - s->field_order = AV_FIELD_PROGRESSIVE; + av_free(buf2); +} - break; +/** + * Find the end of the current frame in the bitstream. + * @return the position of the first byte of the next frame, or -1 + */ +static int vc1_find_frame_end(ParseContext *pc, const uint8_t *buf, + int buf_size) { + int pic_found, i; + uint32_t state; + + pic_found= pc->frame_start_found; + state= pc->state; + + i=0; + if(!pic_found){ + for(i=0; i<buf_size; i++){ + state= (state<<8) | buf[i]; + if(state == VC1_CODE_FRAME || state == VC1_CODE_FIELD){ + i++; + pic_found=1; + break; + } + } } - if (avctx->framerate.num) - avctx->time_base = av_inv_q(av_mul_q(avctx->framerate, (AVRational){avctx->ticks_per_frame, 1})); - s->format = vpc->v.chromaformat == 1 ? AV_PIX_FMT_YUV420P - : AV_PIX_FMT_NONE; - if (avctx->width && avctx->height) { - s->width = avctx->width; - s->height = avctx->height; - s->coded_width = FFALIGN(avctx->coded_width, 16); - s->coded_height = FFALIGN(avctx->coded_height, 16); + + if(pic_found){ + /* EOF considered as end of frame */ + if (buf_size == 0) + return 0; + for(; i<buf_size; i++){ + state= (state<<8) | buf[i]; + if(IS_MARKER(state) && state != VC1_CODE_FIELD && state != VC1_CODE_SLICE){ + pc->frame_start_found=0; + pc->state=-1; + return i-3; + } + } } + pc->frame_start_found= pic_found; + pc->state= state; + return END_NOT_FOUND; } static int vc1_parse(AVCodecParserContext *s, @@ -130,126 +164,22 @@ static int vc1_parse(AVCodecParserContext *s, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size) { - /* Here we do the searching for frame boundaries and headers at - * the same time. Only a minimal amount at the start of each - * header is unescaped. */ VC1ParseContext *vpc = s->priv_data; - int pic_found = vpc->pc.frame_start_found; - uint8_t *unesc_buffer = vpc->unesc_buffer; - size_t unesc_index = vpc->unesc_index; - VC1ParseSearchState search_state = vpc->search_state; - int start_code_found = 0; - int next = END_NOT_FOUND; - int i = vpc->bytes_to_skip; + int next; - if (pic_found && buf_size == 0) { - /* EOF considered as end of frame */ - memset(unesc_buffer + unesc_index, 0, UNESCAPED_THRESHOLD - unesc_index); - vc1_extract_header(s, avctx, unesc_buffer, unesc_index); - next = 0; - } - while (i < buf_size) { - uint8_t b; - start_code_found = 0; - while (i < buf_size && unesc_index < UNESCAPED_THRESHOLD) { - b = buf[i++]; - unesc_buffer[unesc_index++] = b; - if (search_state <= ONE_ZERO) - search_state = b ? NO_MATCH : search_state + 1; - else if (search_state == TWO_ZEROS) { - if (b == 1) - search_state = ONE; - else if (b > 1) { - if (b == 3) - unesc_index--; // swallow emulation prevention byte - search_state = NO_MATCH; - } - } - else { // search_state == ONE - // Header unescaping terminates early due to detection of next start code - search_state = NO_MATCH; - start_code_found = 1; - break; - } - } - if ((s->flags & PARSER_FLAG_COMPLETE_FRAMES) && - unesc_index >= UNESCAPED_THRESHOLD && - vpc->prev_start_code == (VC1_CODE_FRAME & 0xFF)) - { - // No need to keep scanning the rest of the buffer for - // start codes if we know it contains a complete frame and - // we've already unescaped all we need of the frame header - vc1_extract_header(s, avctx, unesc_buffer, unesc_index); - break; - } - if (unesc_index >= UNESCAPED_THRESHOLD && !start_code_found) { - while (i < buf_size) { - if (search_state == NO_MATCH) { - i += vpc->v.vc1dsp.startcode_find_candidate(buf + i, buf_size - i); - if (i < buf_size) { - search_state = ONE_ZERO; - } - i++; - } else { - b = buf[i++]; - if (search_state == ONE_ZERO) - search_state = b ? NO_MATCH : TWO_ZEROS; - else if (search_state == TWO_ZEROS) { - if (b >= 1) - search_state = b == 1 ? ONE : NO_MATCH; - } - else { // search_state == ONE - search_state = NO_MATCH; - start_code_found = 1; - break; - } - } - } - } - if (start_code_found) { - vc1_extract_header(s, avctx, unesc_buffer, unesc_index); - - vpc->prev_start_code = b; - unesc_index = 0; + if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){ + next= buf_size; + }else{ + next= vc1_find_frame_end(&vpc->pc, buf, buf_size); - if (!(s->flags & PARSER_FLAG_COMPLETE_FRAMES)) { - if (!pic_found && (b == (VC1_CODE_FRAME & 0xFF) || b == (VC1_CODE_FIELD & 0xFF))) { - pic_found = 1; - } - else if (pic_found && b != (VC1_CODE_FIELD & 0xFF) && b != (VC1_CODE_SLICE & 0xFF)) { - next = i - 4; - pic_found = b == (VC1_CODE_FRAME & 0xFF); - break; - } - } - } - } - - vpc->pc.frame_start_found = pic_found; - vpc->unesc_index = unesc_index; - vpc->search_state = search_state; - - if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { - next = buf_size; - } else { if (ff_combine_frame(&vpc->pc, next, &buf, &buf_size) < 0) { - vpc->bytes_to_skip = 0; *poutbuf = NULL; *poutbuf_size = 0; return buf_size; } } - /* If we return with a valid pointer to a combined frame buffer - * then on the next call then we'll have been unhelpfully rewound - * by up to 4 bytes (depending upon whether the start code - * overlapped the input buffer, and if so by how much). We don't - * want this: it will either cause spurious second detections of - * the start code we've already seen, or cause extra bytes to be - * inserted at the start of the unescaped buffer. */ - vpc->bytes_to_skip = 4; - if (next < 0 && next != END_NOT_FOUND) - vpc->bytes_to_skip += next; + vc1_extract_headers(s, avctx, buf, buf_size); *poutbuf = buf; *poutbuf_size = buf_size; @@ -265,9 +195,9 @@ static int vc1_split(AVCodecContext *avctx, while (ptr < end) { ptr = avpriv_find_start_code(ptr, end, &state); - if (state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT) { + if (state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT) charged = 1; - } else if (charged && IS_MARKER(state)) + else if (charged && IS_MARKER(state)) return ptr - 4 - buf; } @@ -278,11 +208,6 @@ static av_cold int vc1_parse_init(AVCodecParserContext *s) { VC1ParseContext *vpc = s->priv_data; vpc->v.s.slice_context_count = 1; - vpc->v.first_pic_header_flag = 1; - vpc->prev_start_code = 0; - vpc->bytes_to_skip = 0; - vpc->unesc_index = 0; - vpc->search_state = NO_MATCH; return ff_vc1_init_common(&vpc->v); }