[deb_ffmpeg.git] / ffmpeg / libavcodec / mpegvideo_parser.c

/*
 * MPEG1 / MPEG2 video parser
 * Copyright (c) 2000,2001 Fabrice Bellard
 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "parser.h"
#include "mpeg12.h"
#include "internal.h"

struct MpvParseContext {
    ParseContext pc;
    AVRational frame_rate;
    int progressive_sequence;
    int width, height;
};


static void mpegvideo_extract_headers(AVCodecParserContext *s,
                                      AVCodecContext *avctx,
                                      const uint8_t *buf, int buf_size)
{
    struct MpvParseContext *pc = s->priv_data;
    const uint8_t *buf_end = buf + buf_size;
    uint32_t start_code;
    int frame_rate_index, ext_type, bytes_left;
    int frame_rate_ext_n, frame_rate_ext_d;
    int top_field_first, repeat_first_field, progressive_frame;
    int horiz_size_ext, vert_size_ext, bit_rate_ext;
    int did_set_size=0;
    int bit_rate = 0;
    int vbv_delay = 0;
//FIXME replace the crap with get_bits()
    s->repeat_pict = 0;

    while (buf < buf_end) {
        start_code= -1;
        buf= avpriv_find_start_code(buf, buf_end, &start_code);
        bytes_left = buf_end - buf;
        switch(start_code) {
        case PICTURE_START_CODE:
            if (bytes_left >= 2) {
                s->pict_type = (buf[1] >> 3) & 7;
                if (bytes_left >= 4)
                vbv_delay = ((buf[1] & 0x07) << 13) | (buf[2] << 5) | (buf[3]  >> 3);
            }
            break;
        case SEQ_START_CODE:
            if (bytes_left >= 7) {
                pc->width  = (buf[0] << 4) | (buf[1] >> 4);
                pc->height = ((buf[1] & 0x0f) << 8) | buf[2];
                if(!avctx->width || !avctx->height || !avctx->coded_width || !avctx->coded_height){
                    ff_set_dimensions(avctx, pc->width, pc->height);
                    did_set_size=1;
                }
                frame_rate_index = buf[3] & 0xf;
                pc->frame_rate.den = avctx->time_base.den = ff_mpeg12_frame_rate_tab[frame_rate_index].num;
                pc->frame_rate.num = avctx->time_base.num = ff_mpeg12_frame_rate_tab[frame_rate_index].den;
                bit_rate = (buf[4]<<10) | (buf[5]<<2) | (buf[6]>>6);
                avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
            }
            break;
        case EXT_START_CODE:
            if (bytes_left >= 1) {
                ext_type = (buf[0] >> 4);
                switch(ext_type) {
                case 0x1: /* sequence extension */
                    if (bytes_left >= 6) {
                        horiz_size_ext = ((buf[1] & 1) << 1) | (buf[2] >> 7);
                        vert_size_ext = (buf[2] >> 5) & 3;
                        bit_rate_ext = ((buf[2] & 0x1F)<<7) | (buf[3]>>1);
                        frame_rate_ext_n = (buf[5] >> 5) & 3;
                        frame_rate_ext_d = (buf[5] & 0x1f);
                        pc->progressive_sequence = buf[1] & (1 << 3);
                        avctx->has_b_frames= !(buf[5] >> 7);

                        pc->width  |=(horiz_size_ext << 12);
                        pc->height |=( vert_size_ext << 12);
                        bit_rate = (bit_rate&0x3FFFF) | (bit_rate_ext << 18);
                        if(did_set_size)
                            ff_set_dimensions(avctx, pc->width, pc->height);
                        avctx->time_base.den = pc->frame_rate.den * (frame_rate_ext_n + 1) * 2;
                        avctx->time_base.num = pc->frame_rate.num * (frame_rate_ext_d + 1);
                        avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
                    }
                    break;
                case 0x8: /* picture coding extension */
                    if (bytes_left >= 5) {
                        top_field_first = buf[3] & (1 << 7);
                        repeat_first_field = buf[3] & (1 << 1);
                        progressive_frame = buf[4] & (1 << 7);

                        /* check if we must repeat the frame */
                        s->repeat_pict = 1;
                        if (repeat_first_field) {
                            if (pc->progressive_sequence) {
                                if (top_field_first)
                                    s->repeat_pict = 5;
                                else
                                    s->repeat_pict = 3;
                            } else if (progressive_frame) {
                                s->repeat_pict = 2;
                            }
                        }

                        if (!pc->progressive_sequence) {
                            if (top_field_first)
                                s->field_order = AV_FIELD_TT;
                            else
                                s->field_order = AV_FIELD_BB;
                        } else
                            s->field_order = AV_FIELD_PROGRESSIVE;
                    }
                    break;
                }
            }
            break;
        case -1:
            goto the_end;
        default:
            /* we stop parsing when we encounter a slice. It ensures
               that this function takes a negligible amount of time */
            if (start_code >= SLICE_MIN_START_CODE &&
                start_code <= SLICE_MAX_START_CODE)
                goto the_end;
            break;
        }
    }
 the_end: ;
    if (avctx->codec_id == AV_CODEC_ID_MPEG2VIDEO && bit_rate) {
        avctx->rc_max_rate = 400*bit_rate;
    }
    if (bit_rate &&
        ((avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO && bit_rate != 0x3FFFF) || vbv_delay != 0xFFFF)) {
        avctx->bit_rate = 400*bit_rate;
    }
}

static int mpegvideo_parse(AVCodecParserContext *s,
                           AVCodecContext *avctx,
                           const uint8_t **poutbuf, int *poutbuf_size,
                           const uint8_t *buf, int buf_size)
{
    struct MpvParseContext *pc1 = s->priv_data;
    ParseContext *pc= &pc1->pc;
    int next;

    if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
        next= buf_size;
    }else{
        next= ff_mpeg1_find_frame_end(pc, buf, buf_size, s);

        if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
            *poutbuf = NULL;
            *poutbuf_size = 0;
            return buf_size;
        }

    }
    /* we have a full frame : we just parse the first few MPEG headers
       to have the full timing information. The time take by this
       function should be negligible for uncorrupted streams */
    mpegvideo_extract_headers(s, avctx, buf, buf_size);
    av_dlog(NULL, "pict_type=%d frame_rate=%0.3f repeat_pict=%d\n",
            s->pict_type, (double)avctx->time_base.den / avctx->time_base.num, s->repeat_pict);

    *poutbuf = buf;
    *poutbuf_size = buf_size;
    return next;
}

static int mpegvideo_split(AVCodecContext *avctx,
                           const uint8_t *buf, int buf_size)
{
    int i;
    uint32_t state= -1;
    int found=0;

    for(i=0; i<buf_size; i++){
        state= (state<<8) | buf[i];
        if(state == 0x1B3){
            found=1;
        }else if(found && state != 0x1B5 && state < 0x200 && state >= 0x100)
            return i-3;
    }
    return 0;
}

static int mpegvideo_parse_init(AVCodecParserContext *s)
{
    s->pict_type = AV_PICTURE_TYPE_NONE; // first frame might be partial
    return 0;
}

AVCodecParser ff_mpegvideo_parser = {
    .codec_ids      = { AV_CODEC_ID_MPEG1VIDEO, AV_CODEC_ID_MPEG2VIDEO },
    .priv_data_size = sizeof(struct MpvParseContext),
    .parser_init    = mpegvideo_parse_init,
    .parser_parse   = mpegvideo_parse,
    .parser_close   = ff_parse_close,
    .split          = mpegvideo_split,
};
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* MPEG1 / MPEG2 video parser
	3	* Copyright (c) 2000,2001 Fabrice Bellard
	4	* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
	5	*
	6	* This file is part of FFmpeg.
	7	*
	8	* FFmpeg is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
	10	* License as published by the Free Software Foundation; either
	11	* version 2.1 of the License, or (at your option) any later version.
	12	*
	13	* FFmpeg is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* Lesser General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU Lesser General Public
	19	* License along with FFmpeg; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	21	*/
	22
	23	#include "parser.h"
	24	#include "mpeg12.h"
	25	#include "internal.h"
	26
	27	struct MpvParseContext {
	28	ParseContext pc;
	29	AVRational frame_rate;
	30	int progressive_sequence;
	31	int width, height;
	32	};
	33
	34
	35	static void mpegvideo_extract_headers(AVCodecParserContext *s,
	36	AVCodecContext *avctx,
	37	const uint8_t *buf, int buf_size)
	38	{
	39	struct MpvParseContext *pc = s->priv_data;
	40	const uint8_t *buf_end = buf + buf_size;
	41	uint32_t start_code;
	42	int frame_rate_index, ext_type, bytes_left;
	43	int frame_rate_ext_n, frame_rate_ext_d;
	44	int top_field_first, repeat_first_field, progressive_frame;
	45	int horiz_size_ext, vert_size_ext, bit_rate_ext;
	46	int did_set_size=0;
	47	int bit_rate = 0;
	48	int vbv_delay = 0;
	49	//FIXME replace the crap with get_bits()
	50	s->repeat_pict = 0;
	51
	52	while (buf < buf_end) {
	53	start_code= -1;
	54	buf= avpriv_find_start_code(buf, buf_end, &start_code);
	55	bytes_left = buf_end - buf;
	56	switch(start_code) {
	57	case PICTURE_START_CODE:
	58	if (bytes_left >= 2) {
	59	s->pict_type = (buf[1] >> 3) & 7;
	60	if (bytes_left >= 4)
	61	vbv_delay = ((buf[1] & 0x07) << 13) \| (buf[2] << 5) \| (buf[3] >> 3);
	62	}
	63	break;
	64	case SEQ_START_CODE:
65	if (bytes_left >= 7) {
66	pc->width = (buf[0] << 4) \| (buf[1] >> 4);
67	pc->height = ((buf[1] & 0x0f) << 8) \| buf[2];
68	if(!avctx->width \|\| !avctx->height \|\| !avctx->coded_width \|\| !avctx->coded_height){
69	ff_set_dimensions(avctx, pc->width, pc->height);
70	did_set_size=1;
71	}
72	frame_rate_index = buf[3] & 0xf;
73	pc->frame_rate.den = avctx->time_base.den = ff_mpeg12_frame_rate_tab[frame_rate_index].num;
74	pc->frame_rate.num = avctx->time_base.num = ff_mpeg12_frame_rate_tab[frame_rate_index].den;
75	bit_rate = (buf[4]<<10) \| (buf[5]<<2) \| (buf[6]>>6);
76	avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
77	}
78	break;
79	case EXT_START_CODE:
80	if (bytes_left >= 1) {
81	ext_type = (buf[0] >> 4);
82	switch(ext_type) {
83	case 0x1: /* sequence extension */
84	if (bytes_left >= 6) {
85	horiz_size_ext = ((buf[1] & 1) << 1) \| (buf[2] >> 7);
86	vert_size_ext = (buf[2] >> 5) & 3;
87	bit_rate_ext = ((buf[2] & 0x1F)<<7) \| (buf[3]>>1);
88	frame_rate_ext_n = (buf[5] >> 5) & 3;
89	frame_rate_ext_d = (buf[5] & 0x1f);
90	pc->progressive_sequence = buf[1] & (1 << 3);
91	avctx->has_b_frames= !(buf[5] >> 7);
92
93	pc->width \|=(horiz_size_ext << 12);
94	pc->height \|=( vert_size_ext << 12);
95	bit_rate = (bit_rate&0x3FFFF) \| (bit_rate_ext << 18);
96	if(did_set_size)
97	ff_set_dimensions(avctx, pc->width, pc->height);
98	avctx->time_base.den = pc->frame_rate.den * (frame_rate_ext_n + 1) * 2;
99	avctx->time_base.num = pc->frame_rate.num * (frame_rate_ext_d + 1);
100	avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
101	}
102	break;
103	case 0x8: /* picture coding extension */
104	if (bytes_left >= 5) {
105	top_field_first = buf[3] & (1 << 7);
106	repeat_first_field = buf[3] & (1 << 1);
107	progressive_frame = buf[4] & (1 << 7);
108
109	/* check if we must repeat the frame */
110	s->repeat_pict = 1;
111	if (repeat_first_field) {
112	if (pc->progressive_sequence) {
113	if (top_field_first)
114	s->repeat_pict = 5;
115	else
116	s->repeat_pict = 3;
117	} else if (progressive_frame) {
118	s->repeat_pict = 2;
119	}
120	}
121
122	if (!pc->progressive_sequence) {
123	if (top_field_first)
124	s->field_order = AV_FIELD_TT;
125	else
126	s->field_order = AV_FIELD_BB;
127	} else
128	s->field_order = AV_FIELD_PROGRESSIVE;
129	}
130	break;
131	}
132	}
133	break;
134	case -1:
135	goto the_end;
136	default:
137	/* we stop parsing when we encounter a slice. It ensures
138	that this function takes a negligible amount of time */
139	if (start_code >= SLICE_MIN_START_CODE &&
140	start_code <= SLICE_MAX_START_CODE)
141	goto the_end;
142	break;
143	}
144	}
145	the_end: ;
146	if (avctx->codec_id == AV_CODEC_ID_MPEG2VIDEO && bit_rate) {
147	avctx->rc_max_rate = 400*bit_rate;
148	}
149	if (bit_rate &&
150	((avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO && bit_rate != 0x3FFFF) \|\| vbv_delay != 0xFFFF)) {
151	avctx->bit_rate = 400*bit_rate;
152	}
153	}
154
155	static int mpegvideo_parse(AVCodecParserContext *s,
156	AVCodecContext *avctx,
157	const uint8_t *poutbuf, int poutbuf_size,
158	const uint8_t *buf, int buf_size)
159	{
160	struct MpvParseContext *pc1 = s->priv_data;
161	ParseContext *pc= &pc1->pc;
162	int next;
163
164	if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
165	next= buf_size;
166	}else{
167	next= ff_mpeg1_find_frame_end(pc, buf, buf_size, s);
168
169	if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
170	*poutbuf = NULL;
171	*poutbuf_size = 0;
172	return buf_size;
173	}
174
175	}
176	/* we have a full frame : we just parse the first few MPEG headers
177	to have the full timing information. The time take by this
178	function should be negligible for uncorrupted streams */
179	mpegvideo_extract_headers(s, avctx, buf, buf_size);
180	av_dlog(NULL, "pict_type=%d frame_rate=%0.3f repeat_pict=%d\n",
181	s->pict_type, (double)avctx->time_base.den / avctx->time_base.num, s->repeat_pict);
182
183	*poutbuf = buf;
184	*poutbuf_size = buf_size;
185	return next;
186	}
187
188	static int mpegvideo_split(AVCodecContext *avctx,
189	const uint8_t *buf, int buf_size)
190	{
191	int i;
192	uint32_t state= -1;
193	int found=0;
194
195	for(i=0; i<buf_size; i++){
196	state= (state<<8) \| buf[i];
197	if(state == 0x1B3){
198	found=1;
199	}else if(found && state != 0x1B5 && state < 0x200 && state >= 0x100)
200	return i-3;
201	}
202	return 0;
203	}
204
205	static int mpegvideo_parse_init(AVCodecParserContext *s)
206	{
207	s->pict_type = AV_PICTURE_TYPE_NONE; // first frame might be partial
208	return 0;
209	}
210
211	AVCodecParser ff_mpegvideo_parser = {
212	.codec_ids = { AV_CODEC_ID_MPEG1VIDEO, AV_CODEC_ID_MPEG2VIDEO },
213	.priv_data_size = sizeof(struct MpvParseContext),
214	.parser_init = mpegvideo_parse_init,
215	.parser_parse = mpegvideo_parse,
216	.parser_close = ff_parse_close,
217	.split = mpegvideo_split,
218	};