| Message ID | 20220515201844.370158-1-scott.the.elm@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel,v2] lavf/mpeg.c: improve readability of packet identification logic | expand |
| Context | Check | Description |
|---|---|---|
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
Ping. Still applies cleanly. On 5/15/22 16:18, Scott Theisen wrote: > switch-case over es_type and then perform a linear search over > startcode. > --- > This version doesn't use stdbool.h but is otherwise identical. > > libavformat/mpeg.c | 213 +++++++++++++++++++++++++++------------------ > 1 file changed, 130 insertions(+), 83 deletions(-) > > diff --git a/libavformat/mpeg.c b/libavformat/mpeg.c > index 864b08d8f8..dfa6852453 100644 > --- a/libavformat/mpeg.c > +++ b/libavformat/mpeg.c > @@ -483,6 +483,7 @@ static int mpegps_read_packet(AVFormatContext *s, > AVStream *st; > FFStream *sti; > int len, startcode, i, es_type, ret; > + int identified = 0; > int pcm_dvd = 0; > int request_probe= 0; > enum AVCodecID codec_id = AV_CODEC_ID_NONE; > @@ -523,92 +524,138 @@ redo: > goto found; > } > > + // identify packet encoding > + identified = 1; > es_type = m->psm_es_type[startcode & 0xff]; > - if (es_type == STREAM_TYPE_VIDEO_MPEG1) { > - codec_id = AV_CODEC_ID_MPEG2VIDEO; > - type = AVMEDIA_TYPE_VIDEO; > - } else if (es_type == STREAM_TYPE_VIDEO_MPEG2) { > - codec_id = AV_CODEC_ID_MPEG2VIDEO; > - type = AVMEDIA_TYPE_VIDEO; > - } else if (es_type == STREAM_TYPE_AUDIO_MPEG1 || > - es_type == STREAM_TYPE_AUDIO_MPEG2) { > - codec_id = AV_CODEC_ID_MP3; > - type = AVMEDIA_TYPE_AUDIO; > - } else if (es_type == STREAM_TYPE_AUDIO_AAC) { > - codec_id = AV_CODEC_ID_AAC; > - type = AVMEDIA_TYPE_AUDIO; > - } else if (es_type == STREAM_TYPE_VIDEO_MPEG4) { > - codec_id = AV_CODEC_ID_MPEG4; > - type = AVMEDIA_TYPE_VIDEO; > - } else if (es_type == STREAM_TYPE_VIDEO_H264) { > - codec_id = AV_CODEC_ID_H264; > - type = AVMEDIA_TYPE_VIDEO; > - } else if (es_type == STREAM_TYPE_VIDEO_HEVC) { > - codec_id = AV_CODEC_ID_HEVC; > - type = AVMEDIA_TYPE_VIDEO; > - } else if (es_type == STREAM_TYPE_AUDIO_AC3) { > - codec_id = AV_CODEC_ID_AC3; > - type = AVMEDIA_TYPE_AUDIO; > - } else if (m->imkh_cctv && es_type == 0x91) { > - codec_id = AV_CODEC_ID_PCM_MULAW; > - type = AVMEDIA_TYPE_AUDIO; > - } else if (startcode >= 0x1e0 && startcode <= 0x1ef) { > - static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 }; > - unsigned char buf[8]; > - > - avio_read(s->pb, buf, 8); > - avio_seek(s->pb, -8, SEEK_CUR); > - if (!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1)) > - codec_id = AV_CODEC_ID_CAVS; > - else > - request_probe= 1; > - type = AVMEDIA_TYPE_VIDEO; > - } else if (startcode == PRIVATE_STREAM_2) { > - type = AVMEDIA_TYPE_DATA; > - codec_id = AV_CODEC_ID_DVD_NAV; > - } else if (startcode >= 0x1c0 && startcode <= 0x1df) { > - type = AVMEDIA_TYPE_AUDIO; > - if (m->sofdec > 0) { > - codec_id = AV_CODEC_ID_ADPCM_ADX; > - // Auto-detect AC-3 > - request_probe = 50; > - } else if (m->imkh_cctv && startcode == 0x1c0 && len > 80) { > - codec_id = AV_CODEC_ID_PCM_ALAW; > - request_probe = 50; > - } else { > - codec_id = AV_CODEC_ID_MP2; > - if (m->imkh_cctv) > - request_probe = 25; > + switch (es_type) { > + case STREAM_TYPE_VIDEO_MPEG1: // 0x01 > + case STREAM_TYPE_VIDEO_MPEG2: // 0x02 > + codec_id = AV_CODEC_ID_MPEG2VIDEO; > + type = AVMEDIA_TYPE_VIDEO; > + break; > + case STREAM_TYPE_VIDEO_MPEG4: // 0x10 > + codec_id = AV_CODEC_ID_MPEG4; > + type = AVMEDIA_TYPE_VIDEO; > + break; > + case STREAM_TYPE_VIDEO_H264: // 0x1B > + codec_id = AV_CODEC_ID_H264; > + type = AVMEDIA_TYPE_VIDEO; > + break; > + case STREAM_TYPE_VIDEO_HEVC: // 0x24 > + codec_id = AV_CODEC_ID_HEVC; > + type = AVMEDIA_TYPE_VIDEO; > + break; > + case STREAM_TYPE_AUDIO_MPEG1: // 0x03 > + case STREAM_TYPE_AUDIO_MPEG2: // 0x04 > + codec_id = AV_CODEC_ID_MP3; > + type = AVMEDIA_TYPE_AUDIO; > + break; > + case STREAM_TYPE_AUDIO_AAC: // 0x0F > + codec_id = AV_CODEC_ID_AAC; > + type = AVMEDIA_TYPE_AUDIO; > + break; > + case STREAM_TYPE_AUDIO_AC3: // 0x81 > + codec_id = AV_CODEC_ID_AC3; > + type = AVMEDIA_TYPE_AUDIO; > + break; > + default: > + if (m->imkh_cctv && es_type == 0x91) { > + codec_id = AV_CODEC_ID_PCM_MULAW; > + type = AVMEDIA_TYPE_AUDIO; > + break; > + } > + identified = 0; > + break; > + } > + if (!identified) { > + identified = 1; > + if (startcode < 0x20) { > + identified = 0; > } > - } else if (startcode >= 0x80 && startcode <= 0x87) { > - type = AVMEDIA_TYPE_AUDIO; > - codec_id = AV_CODEC_ID_AC3; > - } else if ((startcode >= 0x88 && startcode <= 0x8f) || > - (startcode >= 0x98 && startcode <= 0x9f)) { > - /* 0x90 - 0x97 is reserved for SDDS in DVD specs */ > - type = AVMEDIA_TYPE_AUDIO; > - codec_id = AV_CODEC_ID_DTS; > - } else if (startcode >= 0xa0 && startcode <= 0xaf) { > - type = AVMEDIA_TYPE_AUDIO; > - if (!pcm_dvd) { > - codec_id = AV_CODEC_ID_MLP; > - } else { > - codec_id = AV_CODEC_ID_PCM_DVD; > + else if (startcode <= 0x3F) { // 0x20 to 0x3F > + type = AVMEDIA_TYPE_SUBTITLE; > + codec_id = AV_CODEC_ID_DVD_SUBTITLE; > } > - } else if (startcode >= 0xb0 && startcode <= 0xbf) { > - type = AVMEDIA_TYPE_AUDIO; > - codec_id = AV_CODEC_ID_TRUEHD; > - } else if (startcode >= 0xc0 && startcode <= 0xcf) { > - /* Used for both AC-3 and E-AC-3 in EVOB files */ > - type = AVMEDIA_TYPE_AUDIO; > - codec_id = AV_CODEC_ID_AC3; > - } else if (startcode >= 0x20 && startcode <= 0x3f) { > - type = AVMEDIA_TYPE_SUBTITLE; > - codec_id = AV_CODEC_ID_DVD_SUBTITLE; > - } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) { > - type = AVMEDIA_TYPE_VIDEO; > - codec_id = AV_CODEC_ID_VC1; > - } else { > + else if (startcode < 0x80) { // 0x40 to 0x7F > + identified = 0; > + } > + else if (startcode <= 0x87) { // 0x80 to 0x87 > + type = AVMEDIA_TYPE_AUDIO; > + codec_id = AV_CODEC_ID_AC3; > + } > + else if (startcode <= 0x8F) { // 0x88 to 0x8F (to 0x9F excluding 0x90 - 0x97) > + type = AVMEDIA_TYPE_AUDIO; > + codec_id = AV_CODEC_ID_DTS; > + } > + else if (startcode <= 0x97) { // exclude 0x90 to 0x97 > + identified = 0; // 0x90 - 0x97 is reserved for SDDS in DVD specs > + } > + else if (startcode <= 0x9F) { // 0x98 to 0x9F (from 0x88 excluding 0x90 - 0x97) > + type = AVMEDIA_TYPE_AUDIO; > + codec_id = AV_CODEC_ID_DTS; > + } > + else if (startcode <= 0xAF) { // 0xA0 to 0xAF > + type = AVMEDIA_TYPE_AUDIO; > + codec_id = (!pcm_dvd) ? AV_CODEC_ID_MLP : AV_CODEC_ID_PCM_DVD; > + } > + else if (startcode <= 0xBF) { // 0xB0 to 0xBF > + type = AVMEDIA_TYPE_AUDIO; > + codec_id = AV_CODEC_ID_TRUEHD; > + } > + else if (startcode <= 0xCF) { // 0xC0 to 0xCF > + /* Used for both AC-3 and E-AC-3 in EVOB files */ > + type = AVMEDIA_TYPE_AUDIO; > + codec_id = AV_CODEC_ID_AC3; > + } > + else if (startcode < 0x1BF) { // 0xD0 to 0x1BE > + identified = 0; > + } > + else if (startcode == PRIVATE_STREAM_2) { // 0x1BF > + type = AVMEDIA_TYPE_DATA; > + codec_id = AV_CODEC_ID_DVD_NAV; > + } > + else if (startcode <= 0x1DF) { // 0x1C0 to 0x1DF > + type = AVMEDIA_TYPE_AUDIO; > + if (m->sofdec > 0) { > + codec_id = AV_CODEC_ID_ADPCM_ADX; > + // Auto-detect AC-3 > + request_probe = 50; > + } > + else if (m->imkh_cctv && startcode == 0x1c0 && len > 80) { > + codec_id = AV_CODEC_ID_PCM_ALAW; > + request_probe = 50; > + } > + else { > + codec_id = AV_CODEC_ID_MP2; > + if (m->imkh_cctv) > + request_probe = 25; > + } > + } > + else if (startcode <= 0x1EF) { // 0x1E0 to 0x1EF > + static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 }; > + unsigned char buf[8]; > + > + avio_read(s->pb, buf, 8); > + avio_seek(s->pb, -8, SEEK_CUR); > + if (!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1)) > + codec_id = AV_CODEC_ID_CAVS; > + else > + request_probe= 1; > + type = AVMEDIA_TYPE_VIDEO; > + } > + else if (startcode < 0xFD55) { // 0x01F0 to 0xFD54 > + identified = 0; > + } > + else if (startcode <= 0xFD5F) { // 0xFD55 to 0xFD5F > + type = AVMEDIA_TYPE_VIDEO; > + codec_id = AV_CODEC_ID_VC1; > + } > + else { > + identified = 0; > + } > + } > + > + if (!identified) { > skip: > /* skip packet */ > avio_skip(s->pb, len);
On Fri, Sep 16, 2022 at 02:33:02PM -0400, Scott Theisen wrote:
> Ping. Still applies cleanly.
iam not against this but iam also not really sure i prefer the new
code.
Maybe other people have a clearer opinion ...
thx
[...]
diff --git a/libavformat/mpeg.c b/libavformat/mpeg.c index 864b08d8f8..dfa6852453 100644 --- a/libavformat/mpeg.c +++ b/libavformat/mpeg.c @@ -483,6 +483,7 @@ static int mpegps_read_packet(AVFormatContext *s, AVStream *st; FFStream *sti; int len, startcode, i, es_type, ret; + int identified = 0; int pcm_dvd = 0; int request_probe= 0; enum AVCodecID codec_id = AV_CODEC_ID_NONE; @@ -523,92 +524,138 @@ redo: goto found; } + // identify packet encoding + identified = 1; es_type = m->psm_es_type[startcode & 0xff]; - if (es_type == STREAM_TYPE_VIDEO_MPEG1) { - codec_id = AV_CODEC_ID_MPEG2VIDEO; - type = AVMEDIA_TYPE_VIDEO; - } else if (es_type == STREAM_TYPE_VIDEO_MPEG2) { - codec_id = AV_CODEC_ID_MPEG2VIDEO; - type = AVMEDIA_TYPE_VIDEO; - } else if (es_type == STREAM_TYPE_AUDIO_MPEG1 || - es_type == STREAM_TYPE_AUDIO_MPEG2) { - codec_id = AV_CODEC_ID_MP3; - type = AVMEDIA_TYPE_AUDIO; - } else if (es_type == STREAM_TYPE_AUDIO_AAC) { - codec_id = AV_CODEC_ID_AAC; - type = AVMEDIA_TYPE_AUDIO; - } else if (es_type == STREAM_TYPE_VIDEO_MPEG4) { - codec_id = AV_CODEC_ID_MPEG4; - type = AVMEDIA_TYPE_VIDEO; - } else if (es_type == STREAM_TYPE_VIDEO_H264) { - codec_id = AV_CODEC_ID_H264; - type = AVMEDIA_TYPE_VIDEO; - } else if (es_type == STREAM_TYPE_VIDEO_HEVC) { - codec_id = AV_CODEC_ID_HEVC; - type = AVMEDIA_TYPE_VIDEO; - } else if (es_type == STREAM_TYPE_AUDIO_AC3) { - codec_id = AV_CODEC_ID_AC3; - type = AVMEDIA_TYPE_AUDIO; - } else if (m->imkh_cctv && es_type == 0x91) { - codec_id = AV_CODEC_ID_PCM_MULAW; - type = AVMEDIA_TYPE_AUDIO; - } else if (startcode >= 0x1e0 && startcode <= 0x1ef) { - static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 }; - unsigned char buf[8]; - - avio_read(s->pb, buf, 8); - avio_seek(s->pb, -8, SEEK_CUR); - if (!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1)) - codec_id = AV_CODEC_ID_CAVS; - else - request_probe= 1; - type = AVMEDIA_TYPE_VIDEO; - } else if (startcode == PRIVATE_STREAM_2) { - type = AVMEDIA_TYPE_DATA; - codec_id = AV_CODEC_ID_DVD_NAV; - } else if (startcode >= 0x1c0 && startcode <= 0x1df) { - type = AVMEDIA_TYPE_AUDIO; - if (m->sofdec > 0) { - codec_id = AV_CODEC_ID_ADPCM_ADX; - // Auto-detect AC-3 - request_probe = 50; - } else if (m->imkh_cctv && startcode == 0x1c0 && len > 80) { - codec_id = AV_CODEC_ID_PCM_ALAW; - request_probe = 50; - } else { - codec_id = AV_CODEC_ID_MP2; - if (m->imkh_cctv) - request_probe = 25; + switch (es_type) { + case STREAM_TYPE_VIDEO_MPEG1: // 0x01 + case STREAM_TYPE_VIDEO_MPEG2: // 0x02 + codec_id = AV_CODEC_ID_MPEG2VIDEO; + type = AVMEDIA_TYPE_VIDEO; + break; + case STREAM_TYPE_VIDEO_MPEG4: // 0x10 + codec_id = AV_CODEC_ID_MPEG4; + type = AVMEDIA_TYPE_VIDEO; + break; + case STREAM_TYPE_VIDEO_H264: // 0x1B + codec_id = AV_CODEC_ID_H264; + type = AVMEDIA_TYPE_VIDEO; + break; + case STREAM_TYPE_VIDEO_HEVC: // 0x24 + codec_id = AV_CODEC_ID_HEVC; + type = AVMEDIA_TYPE_VIDEO; + break; + case STREAM_TYPE_AUDIO_MPEG1: // 0x03 + case STREAM_TYPE_AUDIO_MPEG2: // 0x04 + codec_id = AV_CODEC_ID_MP3; + type = AVMEDIA_TYPE_AUDIO; + break; + case STREAM_TYPE_AUDIO_AAC: // 0x0F + codec_id = AV_CODEC_ID_AAC; + type = AVMEDIA_TYPE_AUDIO; + break; + case STREAM_TYPE_AUDIO_AC3: // 0x81 + codec_id = AV_CODEC_ID_AC3; + type = AVMEDIA_TYPE_AUDIO; + break; + default: + if (m->imkh_cctv && es_type == 0x91) { + codec_id = AV_CODEC_ID_PCM_MULAW; + type = AVMEDIA_TYPE_AUDIO; + break; + } + identified = 0; + break; + } + if (!identified) { + identified = 1; + if (startcode < 0x20) { + identified = 0; } - } else if (startcode >= 0x80 && startcode <= 0x87) { - type = AVMEDIA_TYPE_AUDIO; - codec_id = AV_CODEC_ID_AC3; - } else if ((startcode >= 0x88 && startcode <= 0x8f) || - (startcode >= 0x98 && startcode <= 0x9f)) { - /* 0x90 - 0x97 is reserved for SDDS in DVD specs */ - type = AVMEDIA_TYPE_AUDIO; - codec_id = AV_CODEC_ID_DTS; - } else if (startcode >= 0xa0 && startcode <= 0xaf) { - type = AVMEDIA_TYPE_AUDIO; - if (!pcm_dvd) { - codec_id = AV_CODEC_ID_MLP; - } else { - codec_id = AV_CODEC_ID_PCM_DVD; + else if (startcode <= 0x3F) { // 0x20 to 0x3F + type = AVMEDIA_TYPE_SUBTITLE; + codec_id = AV_CODEC_ID_DVD_SUBTITLE; } - } else if (startcode >= 0xb0 && startcode <= 0xbf) { - type = AVMEDIA_TYPE_AUDIO; - codec_id = AV_CODEC_ID_TRUEHD; - } else if (startcode >= 0xc0 && startcode <= 0xcf) { - /* Used for both AC-3 and E-AC-3 in EVOB files */ - type = AVMEDIA_TYPE_AUDIO; - codec_id = AV_CODEC_ID_AC3; - } else if (startcode >= 0x20 && startcode <= 0x3f) { - type = AVMEDIA_TYPE_SUBTITLE; - codec_id = AV_CODEC_ID_DVD_SUBTITLE; - } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) { - type = AVMEDIA_TYPE_VIDEO; - codec_id = AV_CODEC_ID_VC1; - } else { + else if (startcode < 0x80) { // 0x40 to 0x7F + identified = 0; + } + else if (startcode <= 0x87) { // 0x80 to 0x87 + type = AVMEDIA_TYPE_AUDIO; + codec_id = AV_CODEC_ID_AC3; + } + else if (startcode <= 0x8F) { // 0x88 to 0x8F (to 0x9F excluding 0x90 - 0x97) + type = AVMEDIA_TYPE_AUDIO; + codec_id = AV_CODEC_ID_DTS; + } + else if (startcode <= 0x97) { // exclude 0x90 to 0x97 + identified = 0; // 0x90 - 0x97 is reserved for SDDS in DVD specs + } + else if (startcode <= 0x9F) { // 0x98 to 0x9F (from 0x88 excluding 0x90 - 0x97) + type = AVMEDIA_TYPE_AUDIO; + codec_id = AV_CODEC_ID_DTS; + } + else if (startcode <= 0xAF) { // 0xA0 to 0xAF + type = AVMEDIA_TYPE_AUDIO; + codec_id = (!pcm_dvd) ? AV_CODEC_ID_MLP : AV_CODEC_ID_PCM_DVD; + } + else if (startcode <= 0xBF) { // 0xB0 to 0xBF + type = AVMEDIA_TYPE_AUDIO; + codec_id = AV_CODEC_ID_TRUEHD; + } + else if (startcode <= 0xCF) { // 0xC0 to 0xCF + /* Used for both AC-3 and E-AC-3 in EVOB files */ + type = AVMEDIA_TYPE_AUDIO; + codec_id = AV_CODEC_ID_AC3; + } + else if (startcode < 0x1BF) { // 0xD0 to 0x1BE + identified = 0; + } + else if (startcode == PRIVATE_STREAM_2) { // 0x1BF + type = AVMEDIA_TYPE_DATA; + codec_id = AV_CODEC_ID_DVD_NAV; + } + else if (startcode <= 0x1DF) { // 0x1C0 to 0x1DF + type = AVMEDIA_TYPE_AUDIO; + if (m->sofdec > 0) { + codec_id = AV_CODEC_ID_ADPCM_ADX; + // Auto-detect AC-3 + request_probe = 50; + } + else if (m->imkh_cctv && startcode == 0x1c0 && len > 80) { + codec_id = AV_CODEC_ID_PCM_ALAW; + request_probe = 50; + } + else { + codec_id = AV_CODEC_ID_MP2; + if (m->imkh_cctv) + request_probe = 25; + } + } + else if (startcode <= 0x1EF) { // 0x1E0 to 0x1EF + static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 }; + unsigned char buf[8]; + + avio_read(s->pb, buf, 8); + avio_seek(s->pb, -8, SEEK_CUR); + if (!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1)) + codec_id = AV_CODEC_ID_CAVS; + else + request_probe= 1; + type = AVMEDIA_TYPE_VIDEO; + } + else if (startcode < 0xFD55) { // 0x01F0 to 0xFD54 + identified = 0; + } + else if (startcode <= 0xFD5F) { // 0xFD55 to 0xFD5F + type = AVMEDIA_TYPE_VIDEO; + codec_id = AV_CODEC_ID_VC1; + } + else { + identified = 0; + } + } + + if (!identified) { skip: /* skip packet */ avio_skip(s->pb, len);